A car weighing 1.5 tons in 5 s increases its speed by 10 m / s. What is the sum of the forces acting on the car?

The car is affected by gravity, the reaction force of the support and the traction force, but so the force of gravity weighs the reaction force of the support, therefore the sum of the forces is equal to the traction force, in the absence of friction
Ft = ma;
Ft = m (v-v0) / t;
Ft = 1.5 * 10 ^ 3 * 10/5;
Ft = 3 (kN).