Question

A stone is projected with velocity $80m/s$ making an angle of ${30}^o$ with the horizontal. The horizontal component of its velocity after $2$ second is $(g=10m/s^2)$

• A. $40m/s$
• B. $40\sqrt{3}m/s$
• C. $20m/s$
• D. $20\sqrt{3}m/s$

Answer 1

The correct option is B $40\sqrt{3}m/s$

Since in horizontal, no force is acting.

Hence, $u_x$ will remain same.
$u_x=u\cos {30}^0=80\cos {30}^0=80\times \frac{\sqrt{3}}{2}=40\sqrt{3}$ $m/s$