A car of mass 1500 kg pulls a caravan of mass 1000 kg
Call the
accelerating force (the force between the driving wheels and the road) F
(a) Use F = Ma
where M is the total mass in other words the mass of the car and the caravan because both
are being accelerated.
Acceleration = 1 ms-2 and the total mass is (1500 +
1000) = 2500 kg
Therefore: F = (1500 + 1000) x 1 = 2500 N
However the
caravan must have the same acceleration as the car otherwise they would separate or
squash together.
(b) So accelerating force in the caravan alone (this is the tension in the
coupling) = T
T = ma = 1000x 1 = 1000 N
(c) By Newton's third law when two
bodies are in equilibrium (in this case the car and the caravan) when a force acts on one
body an equal and opposite force acts on the other body.
Therefore: Force on the
car = tension in the coupling = 1000 N