Question

Name the type of energy (kinetic energy $K$ or potential energy $U$) possessed in the following case.

A piece of stone placed on the roof.

• A. $U$
• B. $K$
• C. $U$ and $K$
• D. No energy

Answer 1

Answer: (A)

$U$

When a stone is placed at the roof it is at a certain height that is given by $U=m\times g\times h$

As we have a certain value for $h$ there would be some value for potential energy.

As the stone is at rest at the roof it will not have any kinetic energy as its velocity is zero, $K=1/2(m\times v^2)=0$.

Hence, only potential energy will be there.