Question

A car with a mass 700 kg accelerates uniformly from rest to a velocity of m s-1 in a time of 10 s. the frictional resistance to the motion of the vehicle is assumed to be constant throughout at 0.5 kN. calculate the force accelerating the car.

Answer 1

Assume that $v=30m/s$.

$ma=F-F_f$ $\to$ $F=ma+F_f$

$v=at$

$F=ma+F_f=m\frac{v}{t}+F_f=700\frac{30}{10}+500=2600N=2.6kN$