A car weighing 2.5 tons changed its speed from 72 km / h to 108 km / h in 20 seconds. Determine the force acting on the car.

According to the conditions of the problem:

m = 2.5 t = 2500 kg – vehicle weight;

v0 = 72 km / h = 20 m / s – initial vehicle speed;

v1 = 108 km / h = 30 m / s – the final speed of the vehicle;

t = 20 s – the time during which the car changed its speed from v0 to v1;

It is required to find F – the force acting on the car.

First, let’s find the acceleration:

a = (v1 – v0) / t = (30 -20) / 20 = 10/20 = 0.5 m / s ^ 2

Knowing the acceleration, we calculate the force:

F = m * a = 2500 * 0.5 = 1250 N.

Answer: the force acting on the car is 1250 N.