A tow truck pulls a car along a gravel road.
The force applied by the engine of the tow truck is 9 000 N. The mass of the tow truck is 1 300 kg and the mass of the car is 950 kg. The vehicles are connected to each other by an inelastic tow bar of negligible mass. See the diagram below.
The tow truck and car move at a CONSTANT VELOCITY.
4.1 Define the term frictional force. (2)
4.2 NAME AND STATE the law that explains why the force exerted by the tow truck on the car is the same as the force exerted by the car on the tow truck. (3)
4.3 Draw a labelled free-body diagram indicating all the forces acting on the tow truck. (5)
4.4 If the coefficient of kinetic friction between the tow-truck tyres and the road surface is 0,45, calculate the:
4.4.1 Magnitude of the tension in the tow bar (5)
4.4.2 Coefficient of kinetic friction between the CAR tyres and the road surface (5)
Suddenly the tow bar between the car and the tow truck disconnects and the car comes loose.
4.5 Using a relevant law of motion, explain why the car continues moving forward for a short distance. (3)
4.6 Calculate the acceleration of the car as it comes to a stop after a short distance. (3)
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