Question

A ball falls from a height $h$ in a fluid which offers a resistance $f=kv$. Find the terminal velocity if mass of the ball is $m$.

• A. $\frac{mg}{k}$
• B. $\sqrt{\frac{mgh}{k}}$
• C. $\frac{mg-B}{k}$
• D. none of these

Answer 1

Answer: (A)

$\frac{mg}{k}$

Net force acting on the balls, $F_{net}=mg-f=mg-kv$
For terminal velocity the net force on ball must be zero. so, $mg-k{v}_t=0$
$v_t=\frac{mg}{k}$