Question

A swimmer of mass $60kg$ jumps from height of $5m$ in swimming pool. When it comes in contact with the surface of water, its velocity becomes zero in $0.4s$. The average resistive force is ....... N

• A. $2100$
• B. $2500$
• C. $1000$
• D. $1500$

Answer 1

The correct option is A $2100$

$v=\sqrt{2gh}=\sqrt{2\times 10\times 5}=10m/s$

net force on man,

$=\frac{m(u-v)}{t}=\frac{60(0-10)}{0.4}=-1500N$

weight downwards,

$=60\times 10=600N$

Force exerted by water,

$F=1500+600=2100N$