A plank is being pushed on a frictionless horizontal floor with a constant velocity `u=1.5m/s` .When a block is gently placed on the plank,it slides for a while,acquires velocity of the plank and then moves together with the plank.If the agency pushing the plank has to do a work W = 11.25 J during the sliding of the block,find mass of the block in kg.

A plank is moving on ground with a velocity v and a block is moving on the plank with respect to it with a velocity u as shown in figure. What is the velocity of block with respect to ground ?

A man of mass m moves on a plank of mass M with a constant veloicty u with respect to the plank, as shown in figure. a.If the plank rest on smooth horizontal surface, determine the velocity of the plank. b If the man travels a distasnce L with respect to the plank, find the distance travelled by the plank with respect to te ground.

A horizontal plank has a rectangular block placed on it. The plank starts oscillating vertically and simple harmonically with an amplitude of 40 cm. The block just loses contact with the plank when the latter is at momentary rest Then.

A wooden plank of mass 20 kg is resting on a smooth horizontal floor. A man of mass 60 kg starts moving from one end of the plank to the other end. The length of the plank is 10 m. Find the displacement of the plank over the floor when the man reaches the other end of the plank.

A wooden plank of mass 20kg is resting on a smooth horizontal floor. A man of mass 60kg starts moving from one end of the plank to the other end. The length of the plank is 10m . Find the displacement of the plank over the floor when the man reaches the other end of the plank.

A plank is moving in a horizontal direction with a constant acceleration ahati . A uniform rough cubical block of side l rests on the plank, and is at rest relative to the plank. Let the center of mass of the block be at (0, l//2) at a given instant. If a=g//10 , then the normal reaction exerted by the plank on the block at that instant acts at

A long horizontal plank of mass m is lying on a smooth horizontal surface. A sphere of same mass m and radius r is spinned about its own axis with angular velocity we and gently placed on the plank. The coefficient of friction between the plank and the sphere is mu . After some time the pure rolling of the sphere on the plank will start. Answer the following questions. Find the displacement of the plank till the sphere starts pure rolling.

A plank of mass 2 kg and length 1 m is placed on horizontal floor.A small block of mass 1 kg is placed on top of the plank , at its right extreme end .The coefficient of friction between plank and floor is 0.5 and that between plank and block is 0.2 . If a horizontal force = 30 N starts acting on the plank to the right ,the time after which the block will fall off the plank is (g = 10 ms^(-2))

A planck of mass 5kg is placed on a frictionless horizontal plane. Further a block of mass 1kg is placed over the plank. A massless spring of natural length 2m is fixed to the plank by its one end. The other end of spring is compressed by the block by half of spring's natural length. They system is now released from the rest. What is the velocity of the plank when block leaves the plank? (The stiffness constant of spring is 100N//m )

A plank is moving along a smooth surface with a constant speed V. A block of mass M is gently placed on it. Initially the block slips and then acquires the constant speed (V) same as the plank. Throughout the period, a horizontal force is applied on the plank to keep its speed constant. (a) Find the work performed by the external force. (b) Find the heat developed due to friction between the block and the plank.