Question

a motor of mass 1500 kg accelerates from 50 km/h to 100 km/h in 10 seconds.calculate.
(i)The acceleration in metre/second2.
(ii)The distance travelled.
(iii)The force on the vehicle.

Answer 1

i.
Acceleration is the change in velocity over time.
a = (v,f - v,o) / t
where v,f and v,o are the final and initial velocities respectively, and t is the time.
Substituting,
a = (100 - 50 km/h)*(1000 m / 1 km)*(1 h / 3600 s) / 10 s
a = 1.39 m/s^2

ii.
Since the motion is uniformly accelerated, we use this formula to get the distance:
d = (v,o)t + (1/2)at^2
Substituting,
d = (50)*(1000/3600)*(10) + 0.5(1.39)(10^2)
d = 208.3 m

iii.
Force is mass x acceleration:
F = ma
Substituting,
F = 1500 * 1.39
F = 2083.3 N

Hope this helps :)