Suppose a ball of mass m is thrown vertically upward with an initial speed v, its
speed decreases continuously till it becomes zero. Thereafter, the ball begins to
fall downward and attains the speed v again before striking the ground. It
implies that the magnitude of initial and final momentums of the ball are same.
Yet, it is not an example of conservation of momentum. Explain why ?
A horse continues to apply a force in order to move a cart with a constant speed. Explain why?
Two identical bullets are fired one by a light rifle and another by a heavy rifle with the same force. Which rifle will hurt the shoulder more and why?
Two identical bullets are fired one by a light rifle and another by a heavy rifle with the same force. Which rifle will hurt the shoulder more and why?
Two balls of the same size but of different materials, rubber and iron are
kept on the smooth floor of a moving train. The brakes are applied suddenly
to stop the train. Will the balls start rolling? If so, in which direction? Will
they move with the same speed? Give reasons for your answer.
There are three solids made up of aluminium, steel and wood, of the same shape and same volume. Which of them would have highest inertia?
A water tanker filled up to 2/3 of its height is moving with a uniform speed.
On sudden application of the brake, the water in the tank would
(a) move backward
(b) move forward
(c) be unaffected
(d) rise upwards
Rocket works on the principle of conservation of
(a) mass
(b) energy
(c) momentum
(d) velocity
A passenger in a moving train tosses a coin which falls behind him. It
means that motion of the train is
(a) accelerated
(b) uniform
(c) retarded
(d) along circular tracks