Question

Two bodies $A$ (of mass 1 kg) and $B$ (of mass 3 kg) are dropped from height of 16 m and 25 m, respectively. The ratio of the time taken by them to reach the ground is

• A. $\frac{4}{5}$
• B. $\frac{5}{4}$
• C. $\frac{12}{5}$
• D. $\frac{5}{12}$

Answer 1

The correct option is A $\frac{4}{5}$

Time taken by a body to fall from a height $h$ to reach the ground is $t=\sqrt{\frac{2h}{g}}$.
$\therefore \frac{t_A}{t_B}=\frac{\sqrt{\frac{2h_A}{g}}}{\sqrt{\frac{2h_B}{g}}}=\sqrt{\frac{h_A}{h_B}}=\sqrt{\frac{16}{25}}=\frac{4}{5}$
Hence, the correct answer is option (a).