Question

A ball is thrown vertically upwards, and it rises to a height of $10\text{m}$. The velocity with which it was thrown upwards is -

• A. $10\text{m/s}$
• B. $14\text{m/s}$
• C. $12\text{m/s}$
• D. $16\text{m/s}$

Answer 1

The correct option is B $14\text{m/s}$

On applying law of conservation of mechanical energy,

Loss in kinetic energy $=$ Gain in potential energy

$\Rightarrow \frac{1}{2}m{v}^2-0=mgh-0$

$\Rightarrow v=\sqrt{2gh}=\sqrt{2\times 10\times 10}\approx 14\text{m/s}$