# Moving from a state of rest, a car weighing 1.5 tons reached a speed of 30 m / s 20 s after

**Moving from a state of rest, a car weighing 1.5 tons reached a speed of 30 m / s 20 s after the start of movement. Determine the thrust force of the vehicle engine.**

m = 1.5 t = 1500 kg.

t = 20 s.

V0 = 0 m / s.

V = 30 m / s.

Fт -?

If the force of resistance to motion is neglected, then according to 2 Newton’s law, the thrust force F of the engine will be the product of the mass of the car m and its acceleration a: F = m * a.

Since the car increases its speed from V0 to V in time t, then its acceleration is expressed by the formula: a = (V – V0) / t.

The formula for determining the traction force of a car will take the form: F = m * (V – V0) / t.

F = 1500 kg * (30 m / s – 0 m / s) / 20 s = 2250 N.

Answer: when driving, the traction force of the car is F = 2250 N.