A block of mass m is placed on a surface with a vertical cross section given by y = x³/6. If the coefficient of friction is 0.5 the maximum height above the ground at which the block can be placed without slipping is :

In the figure at the free end a force F is applied to keep the suspended mass of 18 kg at rest . The value of F is- 

A light spring is compressed and placed horizontally between a vertical fixed wall and a block, free to slide over a smooth horizontal table top as shown in figure. If the system is released from rest, which of the graphs below represents the relation between the acceleration ‘a’ of the block and the distance ‘x’ travelled by it? 

A stretching force of 1000 newton is applied at one end of a spring balance and an equal stretching force is applied at the other end at the same time. The reading of the balance will be -

Two objects A and B are thrown upward simultaneously with the same speed. The mass of A is greater than the mass of B. Suppose the air exerts a constant and equal force of resistance on the two bodies-

A small block of mass m is placed on a bigger block of mass M, which is placed on a horizontal frictionless plane. The two blocks are given equal speeds u, but in opposite directions, as shown in the figure. 

After sometime, it is observed that both the blocks are moving in the direction of motion of the lower block, with a velocity greater than . It can be concluded that

Friction coefficient between any two surfaces in contact is 0.5. Pulleys and strings are frictionless. Friction between blocks A and B and tension in string connecting block A and B are respectively. (in Newton) 

A solid sphere rolls down an inclined plane without slipping on the surface. Then the force of friction acting on the sphere is