Question

A particle of mass $5\text{kg}$ is projected vertically upwards from point $D$ on the ground. The ratio of potential energy at point $B$ and at point $A$ is (take point D as reference)

• A. $1:3$
• B. $3:1$
• C. $3:2$
• D. $3:4$

Answer 1

The correct option is A $1:3$

Here, ground $\left(D\right)$ is taken as reference.
$P{E}_A=$ Potential energy at $A$ $=mgH$
$P{E}_B=$ Potential energy at $B$ $=mg\left(\frac{H}{3}\right)$

$\therefore \frac{P{E}_B}{P{E}_A}=\frac{mg\left(\frac{H}{3}\right)}{mg\left(H\right)}=1:3$