The force that causes your car to gain momentum when going downhill is known as gravity. true / false.

TRUE.   The weight component is responsible for acceleration and therefore the increase in vehicle speed,

Explanation:

Let's write Newton's second law for the car down a slope

Y Axis

         N-Wy = 0

         N = Wy

X axis

        Wx -fr= m a

Using trigonometry

        sin θ = Wx / W

        cos θ = Wy / W

         Wx = W sin θ

         Wy = W cos θ

We replace

             W sin θ - fr = m a

The weight component is responsible for acceleration and therefore the increase in vehicle speed,

fr is the force of car brakes

Consequently, of the above TRUTH