Question

A ball is thrown in the air with speed $V_0$ upward. The speed when it reaches half of its maximum height is

• A. $0.25V_0$
• B. $0.5V_0$
• C. $0.707V_0$
• D. $0.6V_0$

Answer 1

Answer: (C)

$0.707V_0$

Maximum Height $\left(H_{max}\right)=\frac{V_0^2}{2g}$

Using $3^{rd}$ equation of motion,

$v^2=u^2-2gh$

where,

$v=$ Speed when it reaches half of maximum height

$g=$ Acceleration due to gravity

$h=\frac{H_{max}}{2}=\frac{V_0^2}{4g}$

$\Rightarrow v^2=V_0^2-2g\left(\frac{V_0^2}{4g}\right)$

$\Rightarrow v^2=\frac{V_0^2}{2}$

$\Rightarrow v=\frac{V_0}{\sqrt{2}}$

$=0.707V_0$

So, the coorect option will be (C).