Question

if a car is accelerating downhill under a net force of 3674 N, what additional force would cause the car to have a constant velocity?

Answer 1

Hi there!

For an object to have a constant velocity, the SUM of the forces must equal 0. This means that the forces are balanced.

When a car is accelerating downhill, it is experiencing a force due to gravity of F = MgsinФ.

In order to balance the forces, there must be an equal and OPPOSITE force acting on the object. This would be a force of kinetic friction.

Thus:

∑F = -F (Kinetic Friction) + MgsinФ

0 = -F (Kinetic Friction) + MgsinФ

MgsinФ = F (Kinetic Friction)

Thus, the force of Kinetic Friction = -3674 N

(Negative indicates in the opposite direction)