Question

A stone is projected horizontally from a cliff at 10 m/sec and lands on the ground at 20 m form the bases of the cliff. Find the height of the cliff. Use $g=10m/s^2$

• A. 18 m
• B. 20 m
• C. 22 m
• D. 24 m

Answer 1

The correct option is B 20 m

$x={\dot{x}}_{o}t$

$20=10\times t$

$\therefore t=2sec$

$y=V_{y_o}t+\frac{1}{2}g{t}^2[\because V_{y_o}=0]$

$=0+\frac{1}{2}\times 10\times (2{)}^2$

$=20m$