A car with a mass of 2 tons, moving away, picks up speed of 36 km / h in 40 seconds and then moves in a straight line evenly.

A car with a mass of 2 tons, moving away, picks up speed of 36 km / h in 40 seconds and then moves in a straight line evenly. Before the intersection, the car brakes and stops after 8 seconds. What is the resultant of the forces applied to it during acceleration? With rectilinear uniform motion? When braking?

A1 = 10 m / s / 40 s = 0.25 m / s ^ 2
a2 = 0
a3 = 10 m / s / 8 s = 1.25 m / s ^ 2
F1 = ma1 = 2000 * 0.25 = 500 H – acceleration
F2 = ma2 = 2000 * 0 = 0 H – uniform movement
F3 = ma3 = 2000 * 1.25 = 2500 H – braking