# Question #3fd94

Apr 30, 2016

1036N,1036N and 2590N

#### Explanation:

The trailer is accelerated at $1.85 m {s}^{-} 2$. Hence the force exerted on it, by Newton's 2nd law, is given by:
$F = m a = 560 \cdot 1.85 = 1036 N$

Newton's 3rd law tells us that if the car exerts a force on the trailer, then the trailer exerts an equal an opposite force on the car. So the answer is $1036 N$

The caravan and car are both accelerating at the same rate. So the engine must be providing a force given by:
$F = m a = \left(1400 + 560\right) \cdot 1.85 = 3626 N$

The net force on the car must therefore be:
Force provide by engine less force exerted by trailer $= 3626 N - 1036 N = 2590 N$

Or you could just say the car is accelerating and therefore the net force must be:
$F = m a = 1400 \cdot 1.85 = 2590 N$

i.e. you get to the same answer