Question

A body is Dropped from a height of hundred meter . Find kinetic and potential energy of body at 25 m from ground if mass of body is 20 kg

Answer 1

Answer:

KE = 15000J

PE = 5000J

Explanation:

Height which the body has been dropped from (h) = 100m

Height which it reaches after travelling (h') = 25m

Potential Energy (PE) at h' = mgh'

Mass (m) = 20 kg

Acceleration due to gravity (g) = 10 $\frac{m}{s^{2} }$

PE = 20 X 10 X 25 = 5000 J

Kinetic Energy (KE) = 1/2 m $v^{2}$

Velocity (v) = $\sqrt{2gh''}$ where h'' is the distance travelled which is 100m - 25m = 75m

KE = 1/2 x 20 x 2 x g x h

= 20gh = 20x10x75 = 15000 J