Question

a man drops 15 kg rock from the top of a ladder of 2 m . what will be its kinetic energy when it reaches the ground and what will be its speed just before it hits the ground take G is equal to 10 metre per second square

Answer 1

#Answered@C29

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Answer 2

Answer:

Mass of body = 15 kg

height = h = 2m

Velocity on reaching the ground = v

Initial velocity = u = 0

V^2 = u^2 + 2as

V^2 = 2gh

v = root (2gh)

v = root (2 × 10m/s^2 × 2m) = root 40 m/s

v = 10 root 2 m/s

Kinetic energy = 1/2 mv^2 = 1/2 × 15 × (10 root 2)^2

K.E = 10^2 × (root 2)^2 × 15/2

K.E = 100 × 2 × 15/2 = 200 × 15/2 = 100 × 15 = 1500 J