Question

PLEASE ANSWER!!
A mass 5 kg starts sliding from A on a smooth surface shown in the figure find the velocity of the mass at B and C. in the figure a body starts sliding from a point A which is 5m above the ground, slides down to the ground and climbs up to point B which is 2.5m above the ground. The ball slides down to the ground and climbs up to a point C which is 5m above the ground.

Answer 1

The velocity of the ball at point B is 7 m/s, and at point C the velocity of the ball is 0 m/s.

At point A, ball has a potential energy only

Now according the law of energy conservation, the total energy of a particle must be conserved.

When ball moves from point A  to point B,

Change in potential energy= Change in kinetic energy

mg(5-2.5)=0.5m((v_b)^2-0)

on solving

v_b=7 m/s

When ball moves from point A to point C,

Change in potential energy= Change in kinetic energy

mg(5-5)=0.5m((v_c)^2-0)

on solving

v_c=0 m/s

Therefore, The velocity of the ball at point B is 7 m/s, and at point C the velocity of the ball is 0 m/s.