Question

A boy playing on the roof of a $10m$ high building throws a ball with a speed of $10m/s$ at an angle of ${30}^0$ with the horizontal. How far from the throwing point will the ball be at the height of $10m$ from the ground? ($g=10m/s^2$)

• A. $8.66m$
• B. $5.20m$
• C. $4.33m$
• D. $2.60m$

Answer 1

Answer: (A)

$8.66m$

Range $R=\frac{u^2\sin 2\theta }{g}=\frac{{10}^2\sin {60}^0}{10}=10\sin {60}^0$
$=8.66m$