Question

A body of mass 'm' is raised from the surface of earth to a point which is at a height $5R$ from the surface of the earth. The change in PE is

• A. 5mgR
• B. $\frac{2mgR}{3}$
• C. $\frac{4}{5}mgr$
• D. $\frac{5mgR}{6}$

Answer 1

The correct option is A 5mgR

Gravitational potential energy $=m\times g\times h$ at least when a specific height is given. So if we add a height of $5R$ the PE will increase by -

$\Rightarrow △PE=(m\times g\times (h+5R))-(m\times g\times h)$

$\therefore$ Change in PE $=(m\times g\times (h+5R))-(m\times g\times h)$

$=(mgh+mg5R)-\left(mgh\right)$

$=mgh+mg5R-mgh$

$=mg5R$

Hence, the answer is $mg5R.$