Question

Two balls are projected horizontally from the top of the building simultaneously with velocities $15m{s}^{-1}and20m{s}^{-1}$ respectively. The ratio of time taken by them to reach the ground is ___.

• A. $2:3$
• B. $3:4$
• C. $1:1$
• D. $4:9$

Answer 1

The correct option is C $1:1$

Time of flight is calculated by $T=\sqrt{\frac{2H}{g}}$

where $H$ is the height from which the projectile is thrown horizontally.

So, time of flight is independent of initial horizontal velocity.

Thus time of flight remains the same for both.

$⟹T_1:T_2=1:1$