A car starts rolling down a hill from rest. After 3 seconds it is moving at 12 m/s. What is the magnitude of this car’s acceleration?

Answer 1

This is a classical mechanics problem. The controlling equation is

v = u + at , here v is final velocity, u is initial velocity and a is net acceleration.

given v = 12 m/s and t= 3sec and u = 0 at start.

solve for a from above equation after substituting

12 = 0 + a*3 gives a = 4m/s^2

I hope this helps.