5. Work, Energy and Power

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Solution

An object moving along horizontal x-direction with kinetic energy 10J is displaced through by the force The kinetic energy of the object at the end of the displacement x is

[NEET 2024 Re]

An object moving along horizontal x-direction with kinetic energy 10J is displaced through by the force The kinetic energy of the object at the end of the displacement x is

[NEET 2024 Re]

An object falls from a height of 10m above the ground. After striking the ground it loses 50% of its kinetic energy. The height upto which the object can rebounce from the ground is:

[NEET 2024 Re]

An object falls from a height of 10m above the ground. After striking the ground it loses 50% of its kinetic energy. The height upto which the object can rebounce from the ground is:

[NEET 2024 Re]

The potential energy of a long spring when stretched by 2cm is U. If the spring is stretched by 8cm, potential energy stored in it will be

[NEET 2023]

The potential energy of a long spring when stretched by 2cm is U. If the spring is stretched by 8cm, potential energy stored in it will be

[NEET 2023]

At any instant of time t, the displacement of any particle is given by 2t − 1 (SI unit) under the influence of force of 5N. The value of instantaneous power is (in SI unit):

[NEET 2024]

At any instant of time t, the displacement of any particle is given by 2t − 1 (SI unit) under the influence of force of 5N. The value of instantaneous power is (in SI unit):

[NEET 2024]

A bullet of mass m hits a block of mass M elastically.

The transfer of energy is the maximum, when :

[NEET 2023 mpr]

A bullet of mass m hits a block of mass M elastically.

The transfer of energy is the maximum, when :

[NEET 2023 mpr]

A particle moves with a velocity horizontally under the action of constant force The instantaneous power supplied to the particle is :

[NEET 2023 mpr]

A particle moves with a velocity horizontally under the action of constant force The instantaneous power supplied to the particle is :

[NEET 2023 mpr]

An electric lift with a maximum load of 2000kg (lift + passengers) is moving up with a constant speed of 1.5ms−1. The frictional force opposing the motion is 3000N. The minimum power delivered by the motor to the lift in watts is : (g=10ms−2)

An electric lift with a maximum load of 2000kg (lift + passengers) is moving up with a constant speed of 1.5ms−1. The frictional force opposing the motion is 3000N. The minimum power delivered by the motor to the lift in watts is : (g=10ms−2)

The energy that will be ideally radiated by a 100kW transmitter in 1 hour is

The energy that will be ideally radiated by a 100kW transmitter in 1 hour is

The distance covered by a body of mass 5g having linear momentum 0.3‌kg‌m∕s in 5s is:

The distance covered by a body of mass 5g having linear momentum 0.3‌kg‌m∕s in 5s is:

Q.10 In-correct

A uniform rod of length 200 cm and mass 500 g is balanced on a wedge placed at 40 cm mark. A mass of 2 kg is suspended from the rod at 20 cm and another unknown mass 'm' is suspended from the rod at 160 cm mark as shown in the figure. Find the value of 'm' such that the rod is in equilibrium. (g = 10 m/s‌2)

A uniform rod of length 200 cm and mass 500 g is balanced on a wedge placed at 40 cm mark. A mass of 2 kg is suspended from the rod at 20 cm and another unknown mass 'm' is suspended from the rod at 160 cm mark as shown in the figure. Find the value of 'm' such that the rod is in equilibrium. (g = 10 m/s‌2)

Q.11 In-correct

A particle is released from height S from the surface of the Earth. At a certain height its kinetic energy is three times its potential energy. The height from the surface of earth and the speed of the particle at that instant are respectively

A particle is released from height S from the surface of the Earth. At a certain height its kinetic energy is three times its potential energy. The height from the surface of earth and the speed of the particle at that instant are respectively

Q.12 In-correct

Water falls from a height of 60 m at the rate of 15 kg/s to operate a turbine. The losses due to frictional force are 10% of the input energy. How much power is generated by the turbine?
(g = 10 m/s‌2 )

Water falls from a height of 60 m at the rate of 15 kg/s to operate a turbine. The losses due to frictional force are 10% of the input energy. How much power is generated by the turbine?
(g = 10 m/s‌2 )

Q.13 In-correct

Body A of mass 4m moving with speed u collides with another body B of mass 2m, at rest. The collision is head on and elastic in nature. After the collision the fraction of energy lost by the colliding body A is

Body A of mass 4m moving with speed u collides with another body B of mass 2m, at rest. The collision is head on and elastic in nature. After the collision the fraction of energy lost by the colliding body A is

Q.14 In-correct

A force F=20+10y acts on a particle in y -direction where F is in newton and y in meter. Work done by this force to move the particle from y=0 to y=1m is

A force F=20+10y acts on a particle in y -direction where F is in newton and y in meter. Work done by this force to move the particle from y=0 to y=1m is

Q.15 In-correct

A mass m is attached to a thin wire and whirled in a vertical circle. The wire is most likely to break when

A mass m is attached to a thin wire and whirled in a vertical circle. The wire is most likely to break when

Q.16 In-correct

A particle of mass 5m at rest suddenly breaks on its own into three fragments. Two fragments of mass m each move along mutually perpendicular direction with speed v each. The energy released during the process is

A particle of mass 5m at rest suddenly breaks on its own into three fragments. Two fragments of mass m each move along mutually perpendicular direction with speed v each. The energy released during the process is

Q.17 In-correct

A moving block having mass m, collides with another stationary block having mass 4m. The lighter block comes to rest after collision. When the initial velocity of the lighter block is v, then the value of coefficient of restitution (e) will be

A moving block having mass m, collides with another stationary block having mass 4m. The lighter block comes to rest after collision. When the initial velocity of the lighter block is v, then the value of coefficient of restitution (e) will be

Q.18 In-correct

A body initially rest and along a frictionless track from a height h (as shown in the figure) just completes a vertical circle of diameter AB=D. The height h is equal to

A body initially rest and along a frictionless track from a height h (as shown in the figure) just completes a vertical circle of diameter AB=D. The height h is equal to

Q.19 In-correct

Consider a drop of rain water having mass 1 g falling from a height of 1 km. It hits the ground with a speed of 50ms−1. Take 'g' constant with a value 10ms−2.The work don by the (i) gravitational force and the (ii) resistive force of air is

(2017 NEET)

Consider a drop of rain water having mass 1 g falling from a height of 1 km. It hits the ground with a speed of 50ms−1. Take 'g' constant with a value 10ms−2.The work don by the (i) gravitational force and the (ii) resistive force of air is

Q.20 In-correct

A particle of mass 10 g moves along a circle of radius 6.4 cm with a constant tangential acceleration. What is the magnitude of this acceleration if the kinetic energy of the particle becomes equal to 8×10−4J by the end of the second revolution after the beginning of the motion ?

(2016 NEET Phase-I)

A particle of mass 10 g moves along a circle of radius 6.4 cm with a constant tangential acceleration. What is the magnitude of this acceleration if the kinetic energy of the particle becomes equal to 8×10−4J by the end of the second revolution after the beginning of the motion ?

(2016 NEET Phase-I)

Q.21 In-correct

A body of mass 1 kg begins to move under the action of time dependent force

are unit vectors along x and y axis. What power will developed by the force at the time t?

(2016 NEET Phase-I)

A body of mass 1 kg begins to move under the action of time dependent force

are unit vectors along x and y axis. What power will developed by the force at the time t?

(2016 NEET Phase-I)

Q.22 In-correct

What is the minimum velocity with which a body of mass m must enter a vertical loop of radius R so that can complete the loop?

(2016 NEET Phase-I)

What is the minimum velocity with which a body of mass m must enter a vertical loop of radius R so that can complete the loop?

(2016 NEET Phase-I)

Q.23 In-correct

A bullet of mass 10 g moving horizontally with a velocity of 400ms−1 strikes a wood block of mass 2 kg which is suspended by light in extensible string of length 5 m. As a result, the centre of gravity of the block found to rise a vertical distance of 10 cm. The speed of the bullet after it emerges out horizontally from the block will be

(2016 NEET Phase-II)

A bullet of mass 10 g moving horizontally with a velocity of 400ms−1 strikes a wood block of mass 2 kg which is suspended by light in extensible string of length 5 m. As a result, the centre of gravity of the block found to rise a vertical distance of 10 cm. The speed of the bullet after it emerges out horizontally from the block will be

(2016 NEET Phase-II)

Q.24 In-correct

Two identical balls A and B having velocities of 0.5ms−1 and 0.3ms−1 respectively collide elastically in one dimension. The velocities of B and A after the collision respectively will be

(2016 NEET Phase-II)

Two identical balls A and B having velocities of 0.5ms−1 and 0.3ms−1 respectively collide elastically in one dimension. The velocities of B and A after the collision respectively will be

(2016 NEET Phase-II)

Q.25 In-correct

A particle moves from a point (−2

) when a force of (4

)N is applied.How much work has been done by force ?

(2016 NEET Phase-II)

A particle moves from a point (−2

) when a force of (4

)N is applied.How much work has been done by force ?

(2016 NEET Phase-II)

Q.26 In-correct

Two particles A and B, move with constant velocities

.At the initial moment their position vectors are

respectively. The condition for particles A and B for their collision is

Two particles A and B, move with constant velocities

.At the initial moment their position vectors are

respectively. The condition for particles A and B for their collision is

Q.27 In-correct

The heart of a man pump s 5 litres of blood through the arteries per minute at a pressure of150 mm of mercury. If the density of mercury be 13.×103

then the power of heart in watt is

The heart of a man pump s 5 litres of blood through the arteries per minute at a pressure of150 mm of mercury. If the density of mercury be 13.×103

then the power of heart in watt is

Q.28 In-correct

A ball is thrown vertically downwards from a height of 20 m with an initial velocity v0.It collides with the ground, loses 50 percent of its energy in collision and rebounds to the same height. The initial velocity v0 is
(Take g=10ms−2)

A ball is thrown vertically downwards from a height of 20 m with an initial velocity v0.It collides with the ground, loses 50 percent of its energy in collision and rebounds to the same height. The initial velocity v0 is
(Take g=10ms−2)

Q.29 In-correct

On a frictionless surface, a block of mass M moving at speed v collides elastically with another block of same mass M which is initially at rest. After collision the first block moves at an angle 0 to its initial direction and has a speed

The second block's speed after the collision

On a frictionless surface, a block of mass M moving at speed v collides elastically with another block of same mass M which is initially at rest. After collision the first block moves at an angle 0 to its initial direction and has a speed

The second block's speed after the collision

Q.30 In-correct

A particle of mass m is driven by a machine that delivers a constant power k watts. If the particle starts from rest the force on the particle at time t is

A particle of mass m is driven by a machine that delivers a constant power k watts. If the particle starts from rest the force on the particle at time t is

Q.31 In-correct

Two particles of masses m1,m2 move with initial velocities u1 and u2.On collision, one of the particles get excited to higher level, after absorbing energy e. If final velocities of particles be v1 and v2 then we must have

Two particles of masses m1,m2 move with initial velocities u1 and u2.On collision, one of the particles get excited to higher level, after absorbing energy e. If final velocities of particles be v1 and v2 then we must have

Q.32 In-correct

Two similar springs P and Q have spring constants KP and KQ such that KP>KQ.They They are stretched first by the same amount (case a), then by the same force (case b). The work done by the springs WP and WQ are related as, in case (a) and case (b) respectively

Two similar springs P and Q have spring constants KP and KQ such that KP>KQ.They They are stretched first by the same amount (case a), then by the same force (case b). The work done by the springs WP and WQ are related as, in case (a) and case (b) respectively

Q.33 In-correct

A body of mass (4m) is lying in x-y plane at rest. It suddenly explodes into three pieces. Two pieces, each of mass (m) move perpendicular to each other with equal speeds (v). The total kinetic energy generated due to explosion is

A body of mass (4m) is lying in x-y plane at rest. It suddenly explodes into three pieces. Two pieces, each of mass (m) move perpendicular to each other with equal speeds (v). The total kinetic energy generated due to explosion is

Q.34 In-correct

A uniform force of (3

) newton acts on a particle of mass 2 kg. Hence the particle is displaced from position (2

) meter to position (4

) meter The work done by the force on the particle is

(2013 NEET)

A uniform force of (3

) newton acts on a particle of mass 2 kg. Hence the particle is displaced from position (2

) meter to position (4

) meter The work done by the force on the particle is

(2013 NEET)

Q.35 In-correct

A particle with total energy E is moving in a potential energy region U(x). Motion of the particle is restricted to the region when

A particle with total energy E is moving in a potential energy region U(x). Motion of the particle is restricted to the region when

Q.36 In-correct

One coolie takes 1 minute to raise asuitcase through a height of 2‌mathrm‌m but the second coolie takes 30 s to raise the samesuitcase to the same height. The powers of two coolies are in the ratio

One coolie takes 1 minute to raise asuitcase through a height of 2‌mathrm‌m but the second coolie takes 30 s to raise the samesuitcase to the same height. The powers of two coolies are in the ratio

Q.37 In-correct

The potential energy of a particle in a force field is
U=

where A and B are positive constants and r is the distance of particle from the center of the field. For stable equilibrium, the distance of the particle is

The potential energy of a particle in a force field is
U=

where A and B are positive constants and r is the distance of particle from the center of the field. For stable equilibrium, the distance of the particle is

Q.38 In-correct

A solid cylinder of mass 3 kg is rolling on a horizontal surface with velocity 4ms−1. It collides with a horizontal spring of force constant 200Nm−1.The maximum compression produced in the spring will be

A solid cylinder of mass 3 kg is rolling on a horizontal surface with velocity 4ms−1. It collides with a horizontal spring of force constant 200Nm−1.The maximum compression produced in the spring will be

Q.39 In-correct

Two spheres A and B of masses m1 and m2 respectively collide. A is at rest initially and B is moving with velocity v and along x-axis. After collision B has a velocity

in a direction perpendicular to the original direction. The mass A moves after collision in the direction

Two spheres A and B of masses m1 and m2 respectively collide. A is at rest initially and B is moving with velocity v and along x-axis. After collision B has a velocity

in a direction perpendicular to the original direction. The mass A moves after collision in the direction

Q.40 In-correct

A car of mass m starts from rest and accelerates so that the instantaneous power delivered to the car has a constant magnitude P0.The instantaneous velocity of the car is proportional to

(2012 Mains)

A car of mass m starts from rest and accelerates so that the instantaneous power delivered to the car has a constant magnitude P0.The instantaneous velocity of the car is proportional to

(2012 Mains)

Q.41 In-correct

The potential energy of a system increases if work is done

The potential energy of a system increases if work is done

Q.42 In-correct

A body projected vertically from the earth reaches a height equal to earth’s radius before returning to the earth. The power exerted by the gravitational force is greatest

A body projected vertically from the earth reaches a height equal to earth’s radius before returning to the earth. The power exerted by the gravitational force is greatest

Q.43 In-correct

A particle of mass m is released from rest and follows a parabolic path as shown. Assuming that the displacement of the mass from the origin is small, which graph correctly depicts the position of the particle as a function of time?

A particle of mass m is released from rest and follows a parabolic path as shown. Assuming that the displacement of the mass from the origin is small, which graph correctly depicts the position of the particle as a function of time?

Q.44 In-correct

Force F on a particle moving in a straight line varies with distance d as shown in figure. The work done on the particle during its displacement of 12 m is

Force F on a particle moving in a straight line varies with distance d as shown in figure. The work done on the particle during its displacement of 12 m is

Q.45 In-correct

A mass m moving horizontally (along the x-axis) with velocity v collides and sticks to a mass of 3m moving vertically upward (along the y-axis) with velocity 2v.The final velocity of the combination is

(2011 Mains)

A mass m moving horizontally (along the x-axis) with velocity v collides and sticks to a mass of 3m moving vertically upward (along the y-axis) with velocity 2v.The final velocity of the combination is

(2011 Mains)

Q.46 In-correct

A ball moving with velocity 2 m/s collides head on with another stationary ball of double the mass. If the coefficient of restitution is 0.5, then their velocities (in m/s) after collision will be

A ball moving with velocity 2 m/s collides head on with another stationary ball of double the mass. If the coefficient of restitution is 0.5, then their velocities (in m/s) after collision will be

Q.47 In-correct

An engine pumps water through a hose pipe. Water passes through the pipe and leaves it with a velocity of 2 m/s. The mass per unit length of water in the pipe is 100 kg/m. What is the power of the engine?

An engine pumps water through a hose pipe. Water passes through the pipe and leaves it with a velocity of 2 m/s. The mass per unit length of water in the pipe is 100 kg/m. What is the power of the engine?

Q.48 In-correct

A particle of mass M, starting from rest, undergoes uniform acceleration. If the speed acquired in time T is V, the power delivered to the particle is

(2010 Mains)

A particle of mass M, starting from rest, undergoes uniform acceleration. If the speed acquired in time T is V, the power delivered to the particle is

(2010 Mains)

Q.49 In-correct

A block of mass M is attached to the lower end of a vertical spring. The spring is hung from a ceiling and has force constant value k. The mass is released from rest with the spring initially upstretched. The maximum extension produced in the length of the spring will be

A block of mass M is attached to the lower end of a vertical spring. The spring is hung from a ceiling and has force constant value k. The mass is released from rest with the spring initially upstretched. The maximum extension produced in the length of the spring will be

Q.50 In-correct

A body of mass 1 kg is thrown upwards with a velocity 20 m/s. It momentarily comes to rest after attaining a height of 18 m. How much energy is lost due to air friction?
(g=10

A body of mass 1 kg is thrown upwards with a velocity 20 m/s. It momentarily comes to rest after attaining a height of 18 m. How much energy is lost due to air friction?
(g=10

Q.51 In-correct

An explosion blows a rock into three parts. Two parts go off at right angles to each other. These two are, 1 kg first part moving with a velocity of 12ms−1 and 2 kg second part moving with a velocity 8ms−1.If the third part flies off with a velocity of 4ms−1,its mass would be

An explosion blows a rock into three parts. Two parts go off at right angles to each other. These two are, 1 kg first part moving with a velocity of 12ms−1 and 2 kg second part moving with a velocity 8ms−1.If the third part flies off with a velocity of 4ms−1,its mass would be

Q.52 In-correct

An engine pumps water continuously through a hose. Water leaves the hose with a velocity v and m is the mass per unit length of the water jet. What is the rate at which kinetic energy is imparted to water?

An engine pumps water continuously through a hose. Water leaves the hose with a velocity v and m is the mass per unit length of the water jet. What is the rate at which kinetic energy is imparted to water?

Q.53 In-correct

A shell of mass 200 gm is ejected from a gun of mass 4 kg by an explosion that generates 1.05 kJ of energy. The initial velocity of the shell is

A shell of mass 200 gm is ejected from a gun of mass 4 kg by an explosion that generates 1.05 kJ of energy. The initial velocity of the shell is

Q.54 In-correct

Water falls from a height of 60 m at the rate of 15 kg/s to operate a turbine. The losses due to frictional forces are 10% of energy. How much power is generated by the turbine ? (g=10m∕s2)

Water falls from a height of 60 m at the rate of 15 kg/s to operate a turbine. The losses due to frictional forces are 10% of energy. How much power is generated by the turbine ? (g=10m∕s2)

Q.55 In-correct

A vertical spring with force constant k is fixed on a table. A ball of mass m at a height h above the free upper end of the spring falls vertically on the spring so that the spring is compressed by a distance d. The net work done in the process is

A vertical spring with force constant k is fixed on a table. A ball of mass m at a height h above the free upper end of the spring falls vertically on the spring so that the spring is compressed by a distance d. The net work done in the process is

Q.56 In-correct

300 J of work is done in sliding a 2 kg block up an inclined plane of height 10m. Work done against friction is (Take g=10m∕s2)

300 J of work is done in sliding a 2 kg block up an inclined plane of height 10m. Work done against friction is (Take g=10m∕s2)

Q.57 In-correct

The potential energy of a long spring when stretched by 2cm is U . If the spring is stretched by 8cm the potential energy stored in it is

The potential energy of a long spring when stretched by 2cm is U . If the spring is stretched by 8cm the potential energy stored in it is

Q.58 In-correct

A body of mass 3kg is under a constant force which causes a displacement s in metres in it, given by the relation s=

t2 where t is in seconds. Work done by the force in 2 seconds is

A body of mass 3kg is under a constant force which causes a displacement s in metres in it, given by the relation s=

t2 where t is in seconds. Work done by the force in 2 seconds is

Q.59 In-correct

A bomb of mass 30kg at rest explodes into two pieces of masses 18kg and 12kg. The velocity of 18kg mass is 6ms−1. The kinetic energy of the other mass is

A bomb of mass 30kg at rest explodes into two pieces of masses 18kg and 12kg. The velocity of 18kg mass is 6ms−1. The kinetic energy of the other mass is

Q.60 In-correct

A force Facting on an object varies with distance x as shown here. The force is inN and x in m The work done by the force in moving the object from x=0 to x=6m is

A force Facting on an object varies with distance x as shown here. The force is inN and x in m The work done by the force in moving the object from x=0 to x=6m is

Q.61 In-correct

A particle of mass m1 is moving with a velocity v1 and another particle of mass m2 is moving with a velocity v2. Both of them have the same momentum but their different kinetic energies are E1 and E2 respectively. If m1>m2 then

A particle of mass m1 is moving with a velocity v1 and another particle of mass m2 is moving with a velocity v2. Both of them have the same momentum but their different kinetic energies are E1 and E2 respectively. If m1>m2 then

Q.62 In-correct

A ball of mass 2kg and another of mass 4kg are dropped together from a 60 feet tall building. After a fall of 30 feet each towards earth, their respective kinetic energies will be in the ratio of

A ball of mass 2kg and another of mass 4kg are dropped together from a 60 feet tall building. After a fall of 30 feet each towards earth, their respective kinetic energies will be in the ratio of

Q.63 In-correct

A mass of 0.5 kg moving with a speed of 1.5m∕s on a horizontal smooth surface, collides with a nearly weightless spring of force constant k=50N∕m. The maximum compression of the spring would be

A mass of 0.5 kg moving with a speed of 1.5m∕s on a horizontal smooth surface, collides with a nearly weightless spring of force constant k=50N∕m. The maximum compression of the spring would be

Q.64 In-correct

When a long spring is stretched by 2cm its potential energy is U. If the spring is stretched by 10cm, the potential energy stored in it will be

When a long spring is stretched by 2cm its potential energy is U. If the spring is stretched by 10cm, the potential energy stored in it will be

Q.65 In-correct

A stationary particle explodes into two particles of masses m1 and m2 which move in opposite directions with velocities v1 and v2 . The ratio of their kinetic energies

A stationary particle explodes into two particles of masses m1 and m2 which move in opposite directions with velocities v1 and v2 . The ratio of their kinetic energies

Q.66 In-correct

If kinetic energy of a body is increased by 300% then percentage change in momentum will be

If kinetic energy of a body is increased by 300% then percentage change in momentum will be

Q.67 In-correct

A child is sitting on a swing. Its minimum and maximum heights from the ground 0.75m and 2m respectively, its maximum speed will be

A child is sitting on a swing. Its minimum and maximum heights from the ground 0.75m and 2m respectively, its maximum speed will be

Q.68 In-correct

Two springs A and B having spring constant KA and KB(KA=2KB) are stretched by applying force of equal magnitude. If energy stored in spring A is EA then energy stored in B will be

Two springs A and B having spring constant KA and KB(KA=2KB) are stretched by applying force of equal magnitude. If energy stored in spring A is EA then energy stored in B will be

Q.69 In-correct

A particle is projected making an angle of 45° with horizontal having kinetic energyK. The kinetic energy at highest point will be

(2001,1997)

A particle is projected making an angle of 45° with horizontal having kinetic energyK. The kinetic energy at highest point will be

(2001,1997)

Q.70 In-correct

)m∕s, then instantaneous power is

)m∕s, then instantaneous power is

Q.71 In-correct

A mass of 1kg is thrown up with a velocity of 100m∕s. After 5 seconds, it explodes into two parts. One part of mass 400g comes down with a velocity 25m∕s. The velocity of other part is (Take left.g=10ms−2)

A mass of 1kg is thrown up with a velocity of 100m∕s. After 5 seconds, it explodes into two parts. One part of mass 400g comes down with a velocity 25m∕s. The velocity of other part is (Take left.g=10ms−2)

Q.72 In-correct

Two bodies with kinetic energies in the ratio of 4: 1 are moving with equal linear momentum. The ratio of their masses is

Two bodies with kinetic energies in the ratio of 4: 1 are moving with equal linear momentum. The ratio of their masses is

Q.73 In-correct

Two equal masses m1 and m2 moving along the same straight line with velocities +3 m∕s and −5 m∕s respectively collide elastically. Their velocities after the collision will be respectively

Two equal masses m1 and m2 moving along the same straight line with velocities +3 m∕s and −5 m∕s respectively collide elastically. Their velocities after the collision will be respectively

Q.74 In-correct

A force acts on a 3 g particle in such a way that the position of the particle as a function of time is given by x=3t−4t2+t3, where x is in metres and t is in seconds. The work done during the first 4 second is

A force acts on a 3 g particle in such a way that the position of the particle as a function of time is given by x=3t−4t2+t3, where x is in metres and t is in seconds. The work done during the first 4 second is

Q.75 In-correct

A shell, in flight, explodes into four unequal parts. Which of the following is conserved?

A shell, in flight, explodes into four unequal parts. Which of the following is conserved?

Q.76 In-correct

Two bodies of masses m and 4m are moving with equal kinetic energies. The ratio of their linear momenta is

(1998, 1997, 1989)

Two bodies of masses m and 4m are moving with equal kinetic energies. The ratio of their linear momenta is

(1998, 1997, 1989)

Q.77 In-correct

A metal ball of mass 2kg moving with speed of 36km∕h has a head on collision with a stationary ball of mass 3kg. If after collision, both the balls move as a single mass, then the loss in K.E. due to collision is

A metal ball of mass 2kg moving with speed of 36km∕h has a head on collision with a stationary ball of mass 3kg. If after collision, both the balls move as a single mass, then the loss in K.E. due to collision is

Q.78 In-correct

A body moves a distance of 10m along a straight line under the action of a 5N force. If the work done is 25J, then angle between the force and direction of motion of the body is

A body moves a distance of 10m along a straight line under the action of a 5N force. If the work done is 25J, then angle between the force and direction of motion of the body is

Q.79 In-correct

A moving body of mass m and velocity 3‌km∕hour collides with a body at rest of mass 2m and sticks to it. Now the combined mass starts to move. What will be the combined velocity?

A moving body of mass m and velocity 3‌km∕hour collides with a body at rest of mass 2m and sticks to it. Now the combined mass starts to move. What will be the combined velocity?

Q.80 In-correct

The potential energy between two atoms, in a molecule, is given by U(x)=

where a and b are positive constants and x is the distance between the atoms. Theatom is in stable equilibrium, when

The potential energy between two atoms, in a molecule, is given by U(x)=

where a and b are positive constants and x is the distance between the atoms. Theatom is in stable equilibrium, when

Q.81 In-correct

A body, constrained to move in y -direction, is subjected to a force given by

)N. The work doneby this force in moving the body through a distance of 10

m along y -axis, is

A body, constrained to move in y -direction, is subjected to a force given by

)N. The work doneby this force in moving the body through a distance of 10

m along y -axis, is

Q.82 In-correct

The kinetic energy acquired by a mass m in travelling distance d, starting from rest, under the action of a constant force is directly proportional to

The kinetic energy acquired by a mass m in travelling distance d, starting from rest, under the action of a constant force is directly proportional to

Q.83 In-correct

A position dependent force, F=(7−2x+3x2)N acts on a small body of mass 2‌kg and displaces it from x=0 to x=5m. The work done in joule is

(1994, 1992)

A position dependent force, F=(7−2x+3x2)N acts on a small body of mass 2‌kg and displaces it from x=0 to x=5m. The work done in joule is

(1994, 1992)

Q.84 In-correct

When a body moves with a constant speed along a circle

When a body moves with a constant speed along a circle

Q.85 In-correct

Two masses of 1g and 9g are moving with equal kinetic energies. The ratio of the magnitudes of their respective linear momenta is

Two masses of 1g and 9g are moving with equal kinetic energies. The ratio of the magnitudes of their respective linear momenta is

Q.86 In-correct

A particle of mass M is moving in a horizontal circle of radius R with uniform speed v. When it moves from one point to a diametrically opposite point, its

A particle of mass M is moving in a horizontal circle of radius R with uniform speed v. When it moves from one point to a diametrically opposite point, its

Q.87 In-correct

How much water a pump of 2‌kW can raise in one minute to a height of 10m ? (take g=10m∕s2)

How much water a pump of 2‌kW can raise in one minute to a height of 10m ? (take g=10m∕s2)

Q.88 In-correct

A bullet of mass 10g leaves a rifle at an initial velocity of 1000m∕s and strikes the earth at the same level with a velocity of 500m∕s. The work done in joule for overcoming the resistance of air will be

A bullet of mass 10g leaves a rifle at an initial velocity of 1000m∕s and strikes the earth at the same level with a velocity of 500m∕s. The work done in joule for overcoming the resistance of air will be

Q.89 In-correct

The coefficient of restitution e for a perfectly elastic collision is

The coefficient of restitution e for a perfectly elastic collision is

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