A 1030 kg car is pulling a 360 kg trailer. Together, the car and trailer have an acceleration of 2.07 m/s2 directly forward.

How do you find net force on the car and trailer?

2 answers

the car is pulling the trailer with a net force of F=masstrailer*a

The trailer is pulling back on the car with the same force.
You use Newton's second law,

F = M a

If you want the net force on car and trailer TOGETHER,

F = (1030 + 360)*2.07 N

Note that the weight does not appear. It is balanced by the upward force on the tires.