A car is towing a trailer along a straight horizontal road by means of a horizontal tow-rope. The mass of the car is 1400 kg. The mass of the trailer is 700 kg. The car and the trailer are modelled as particles and the tow-rope as a light inextensible string. The resistances to motion of the car and the trailer are assumed to be constant and of magnitude 630 N and 280 N respectively. The driving force on the car, due to its engine, is 2380 N.
Find the acceleration of the car.
Find the tension in the tow-rope.
State how you have used the assumption that the car and trailer are modelled as particles.
When the car and trailer are moving at 12 m s-1, the tow-rope breaks. Assuming that the driving force on the car and the resistances to motion are unchanged, find the distance moved by the car in the first 4 s after the tow-rope breaks.
49 exam-style questions on OCR (MEI) A Level Maths 3.5 Newton's Laws of Motion, covering 3.5.1 Meaning of Newton's three laws, 3.5.2 Equation of motion, 3.5.3 Equation of motion for a particle in a straight line, 3.5.4 Model a system of connected particles, 3.5.5 Equations of motion for individual particles, 3.5.6 System with no relative motion as a single particle, and 3.5.7 Equation of motion in a straight line or plane (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.