Question

A body of mass $0.05kg$ is falling with acceleration $9.4m{s}^{-2}$. The force exerted by air opposite to motion is____________N ($g=9.8m{s}^{-2}$)

• A. $0.02$
• B. $0.20$
• C. $0.030$
• D. Zero

Answer 1

The correct option is A $0.02$

Given mass of the body $m=0.05kg$ and acceleration $a=9.4m/s^2$

Now force exerted by the ball $F_b=0.05\times 9.4=0.47N$

Also force exerted by the air due to acceleration due to gravity$F_{air}=0.05\times 9.8=0.49N$

Thus net force acting on the body when falling $F_{net}=0.49-0.47=0.02N$