A hoop of radius 2 m weighs 100 kg. It rolls along a horizontal floor so that its centre of mass has a speed of `20 cm//s`. How much work has to be done to stop it?

A solid cylinder rolls up an inclined plane of angle of inclination 30^@ . At the bottom of the inclined plane the centre of mass of the cylinder has a speed of 5 m//s :- How long will it take to return to the bottom?

A force acting on a object of mass 500 gm changes its speed from 200 cm/s to 0.2 m/s. The change in momentum is

A solid cylinder rolls up an inclined plane of angle of inclination 30^@ . At the bottom of the inclined plane the centre of mass of the cylinder has a speed of 5 m//s :- How far will the cylinder go up the plane?

A trolley of mass 200 kg moves with a uniform speed of 36 km//h on a frictionless track. A child of mass 20 kg runs on the trolley from one end to the other (10 m away) with a speed of 4 m s^-1 relative to the trolley in a direction opposite to the its motion, and jumps out of the trolley. What is the final speed of the trolley ? How much has the trolley moved from the time the child begins to run ?

A solid disc and a ring, both of radius 10 cm are placed on a horizontal table simultaneously, with initial angular speed equal to 10 pi rad s^-1 . Which of the two will start to roll earlier ? The co-efficient of kinetic friction is mu_k=0.2 .

A girl riding a bicycle along a straight road with a speed of 5 ms^-1 throws a stone of mass 0.5 kg which has a speed of 15 ms^-1 with respect to the ground along her direction of motion. The mass of the girl and bicyle is 50 kg. Does the speed of the bicycle change after the stone is thrown? What is the change in speed, if so?

A constant retarding force of 50 N is applied to a body of mass 20 kg moving initially with a speed of 15m s^-1 . How long does the body take to stop ?

A cylinder of mass 10 kg and radius 15 cm is rolling perfectly on a plane of inclination 30^@ . The co-efficient of static friction mus = 0.25 :- How much is the force of friction acting on the cylinder ?