Physics
A ball of mass m is dropped freely from point A. It is given that AB = BC = CD = h. If the acceleration due to gravity at the given place is g, then what will be its
(a) potential energy at point A?
(b) kinetic energy at point C?
Work, Energy & Power
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Answer
(a) Height of point A = 3h
So, potential energy PA = mg x 3h = 3mgh
(b) At point A, initial velocity = u = 0
At point C, final velocity = v
So, from third equation of motion:
v2 = u2 + 2g x 2h = u2 + 4gh
v2 = 4gh ……………(i)
Kinetic energy at C point, KC =
KC = 2mgh
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