Question

Find the average force needed to accelerate a car weighing $500kg$ from rest to $72km/h$ in a distance of $25m$.

Answer 1

The acceleration of the car is given as,

$v^2=u^2+2as$

${\left(72\times \frac{5}{18}\right)}^2=0+2\times a\times 25$

$a=8m/s^2$

The force is given as,

$F=ma$

$=500\times 8$

$=4000N$

Thus, the average force needed to accelerate the car is $4000N$.