Question

It is required to increase the velocity of a scooter of mass 80 kg from $5m{s}^{-1}$ to $25m{s}^{-1}$ in 2 s. The force required will be:

• A. 200 N
• B. 600 N
• C. 800 N
• D. 100 N

Answer 1

The correct option is C 800 N

Given : $m=80$ kg $u=5$ m/s $v=25$ m/s $t=2$ s

Using $v=u+at$

$\therefore$ $25=5+a\times 2$ $⟹a=10$ $m/s^2$

Thus force required $F=ma=80\times 10=800$ N