A remote-controlled toy car of mass 0.80 kg is driving along a straight horizontal track at a constant velocity of 5.0 m s-1. The car passes over a magnetic braking strip that exerts a force on the car in the opposite direction to its velocity for a short duration. The magnitude of the change in momentum of the car is 6.8 kg m s-1.
Assuming resistive forces other than the braking force are negligible, what is the speed of the toy car after passing over the braking strip?
1.8 m s−11.8\text{ m s}^{-1}1.8 m s−1
3.5 m s−13.5\text{ m s}^{-1}3.5 m s−1
8.5 m s−18.5\text{ m s}^{-1}8.5 m s−1
13.5 m s−113.5\text{ m s}^{-1}13.5 m s−1
8 exam-style questions on OCR A A Level Physics Newton's laws of motion and momentum, covering Newton's laws of motion and Collisions. Each one has a worked solution and a mark scheme showing where the marks go.