Question

What is maximum height of a stone thrown vertically upward, if its velocity is halved in 1.5 s? (g = 10 $m/s^2$ )

• A. 20 m
• B. 25 m
• C. 30 m
• D. 45 m

Answer 1

The correct option is D 45 m

$v=\frac{u}{2}=u-gt$

$=u-\frac{3}{2}g$

$t=1.5s$

$u=30m/s$

$h=\frac{u^2}{2g}$

$h=\frac{30\times 30}{2\times 10}=45m$