A-level · Forces & Newton's laws

Newton's laws and F = maExam-style questions

Newton's three laws and the one equation that runs all of dynamics — the RESULTANT force equals mass times acceleration — applied along a line and to forces given as 2-D vectors, why weight is mg and the normal reaction is whatever balances the rest, and how a lift problem is just F = ma done vertically.

Start practising Read the lesson

12 questions · A-level level · mark scheme and worked solution on each · no sign-up to try

DifficultyAll Level 2 Level 3 Level 4 Level 5

1
Figure 3 shows a car of mass $1200$ kg travelling along a straight road inclined at an angle $\theta$ to the horizontal, where $\sin\theta = \dfrac{1}{14}$ .Figure 3 (not accurately drawn)

The car experiences a constant resistance to motion of $400$ N. Take $g = 9.8$ m s⁻².
(a) The car accelerates up the slope at $0.8$ m s⁻². Find the magnitude of the driving force. (5 marks)
(b) When the car is travelling up the slope at $20$ m s⁻¹ the engine is switched off. The resistance remains $400$ N.

Find the distance the car travels up the slope before coming to instantaneous rest, giving your answer to $3$ significant figures. (5 marks)
(c) Find the time taken for the car to come to instantaneous rest after the engine is switched off, giving your answer to $3$ significant figures. (2 marks)
Level 5 · 12 marksTry it