Question

a body of mass 20 kg Falls through a distance of 50 cm then the loss in potential energy is

Answer 1

potential energy=mass into height into acceleration due to gravity
answer is 98 joule

Answer 2

Answer:  

The loss in potential energy is 98 J.

Solution:

The given data is  

Mass of the body m = 20 kg

Distance of fall h = 50 cm = 0.5 m

Acceleration $\bold{g =9.8\ \mathrm{m} / \mathrm{s}^{2}}$

As ‘potential energy’ is the energy exerted by the gravitational force on the mass of the object to resist its motion. As the body is falling from a height of 50 cm, with mass 20 kg, it will obey a free fall path and hence the acceleration will be acceleration due to gravity.

The ‘potential energy’ is  

$\bold{P . E=M a s s \times \text { acceleration due to gravity } \times \text { height }=m g h}$

So

$\bold{P . E=20 \times 9.8 \times 0.5=98 \mathrm{J}}$

So, the energy lost in the potential energy is 98 J.