The car, moving away, reached a speed of 72 km / h after 100 m. Find the mass of the car if the thrust

The car, moving away, reached a speed of 72 km / h after 100 m. Find the mass of the car if the thrust force of its engine is 2 kN.

Initial data: S (distance traveled by the car) = 100 m, V (speed that the car reached) = 72 km / h = 72 * 1000/3600 = 20 m / s, F (traction force of the car engine) = 2 kN = 2000 N, V0 (initial speed, the car started off) = 0 m / s.

1) Let’s calculate the acceleration that the car will acquire:

S = (V ^ 2 – V0 ^ 2) / 2a = V ^ 2 / 2a.

a = V ^ 2 / 2S = 20 ^ 2 / (2 * 100) = 2 m / s ^ 2.

2) Determine the mass:

F = m * a.

m = F / a = 2000/2 = 1000 kg.

Answer: The mass of this car is 1000 kg.