Question

A stone of mass $200g$ thrown up with a certain velocity reaches a maximum height of $30$ m. Another body of double the mass is thrown up with half the velocity of the first. Maximum height reached by it is

• A. 30 m
• B. 15 m
• C. 7.5 m
• D. 3.5 m

Answer 1

Answer: (C)

7.5 m

$v^2=u^2+2as$

$a=-g$

At highest point, $v=0$

$⟹h\propto u^2$
$\Rightarrow \frac{h_1}{h_2}=\frac{V_1^2}{V_2^2}$$\Rightarrow \frac{30}{h_2}=(\frac{V}{\frac{V}{2}}{)}^2$
$\Rightarrow h_2=\frac{30}{4}=7.5m$