Question

A ball is thrown vertically up (taken as $+z-\text{axis}$) from the ground. The correct momentum-height $(p-h)$ diagram is

• A.
• B.
• C.
• D.

Answer 1

The correct option is A

For motion under gravity $v^2=u^2-2gh$

$v=\sqrt{u^2-2gh}$
Momentum$p=mv$
$\Rightarrow p=m\sqrt{u^2-2gh}$
Therefore graph between $p$ and $h$ is not a straight line.
So Option $\left(b\right)$ and $\left(c\right)$ are not possible.
During upward journey,
as $h$ increases, $p$ decreases and
In downward journey as $h$ decreases $p$ increases.
Therefore Option $\left(D\right)$ is the correct.