Question

How much energy is gained by a box of mass $20kg$ when a man raises the box by $0.5m$ in order to place it inside the bus? $(g=10m{s}^{-2})$

Answer 1

Given;
Mass of the box, m = 20 𝑘𝑔
Raise in elevation,$h=0.5m$
When the man raises the box by $0.5m$, the
work done by him is stored in the box as
gravitational potential energy.
𝑖. 𝑒$.PE=mgh$
$=20\times 10\times 0.5$
$=100J$
∴ Energy gained by the box $=100J$