A spring is kept compressed by a small trolley of mass 0.5 kg lying on a smooth horizontal surface as shown. When the trolley is released, it is found to move at a speed of v = 2 m/s-1. What potential energy did the spring possess when compressed?
A bullet of mass 50g is moving with a velocity of 500m/s-1. It penetrates 10 cm into a still target and comes to rest. Calculate:
A body of mass 10 kg is moving with a velocity 20m s-1. If the mass of the body is doubled and its velocity is halved, find: (i) the initial kinetic energy, and (ii) the final kinetic energy.
A ball of mass 0.5 kg slows down from a speed of 5m/s-1 to that of 3m/s-1. Calculate the change in kinetic energy of the ball.
A car is running at a speed of 15 km h-1 while another similar car is moving at a speed of 45 km h-1. Find the ratio of their kinetic energies.
Two bodies of equal masses are moving with uniform velocities v and 2v. Find the ratio of their kinetic energies.
Calculate the decrease in the kinetic energy of a moving body if its velocity reduces to half of the initial velocity.
