wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

A man drops a 10 kg rock from the top of a 5 m ladder. What is its speed just before it hits the ground? What is its kinetic energy when it reaches the ground? (g = 10 m/s2)

Open in App
Solution

Mass of the body dropped, (m) = 10 kg
Height from which the body is dropped, (h) = 5 m
Initial velocity of the ball, (u) = 0 m/s
Acceleration due to gravity, (g) = 10 m/s2
Let the final velocity of the ball when it just reaches the ground be (v)
We will use the third equation of motion to find the velocity of the body when it just reaches the ground,
v2 = u2 + 2as
So,
v=0+2(10)(5) m/s =10 m/s
Now, we can find the kinetic energy as,
K.E=12mv2
Therefore,
K.E=12(10)(10)2 J =500 J
So, the kinetic energy of the moving object is 500 J.

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
kinetic Energy
PHYSICS
Watch in App
Join BYJU'S Learning Program
CrossIcon