Question

what force is required to move a 25,000 kg vehicle from 0km/hr to 60km/hr in 20 seconds? (hint: convert to proper units, solve fore acceleration, then solve for force)

Answer 1

Let's first convert the initial and final speed of the vehicle in m/s:
$v_i = 0km/h = 0m/s$
$v_f = 60km/h \cdot \frac{1000 m/km}{3600 s/h} =16.67 m/s$

Therefore, the acceleration of the car is given by
$a= \frac{v_f-v_i}{t}= \frac{16.67 m/s-0 m/s}{20 s}=0.83 m/s^2$

And so now we can calculate the force required by using Newton's second law:
$F=ma=(25000 kg)(0.83 m/s^2)=20750 N$