A 1480(k)g car pulls a 300(k)g trailer. The car exerts a horizontal force of 3900(N) against the ground in order to accelerate.
What force does the car exert on the trailer? Assume an effective friction coefficient of 0.15 for the trailer.
My question really is how to solve this problem correctly, but more so, correcting the mistakes I have made in my attempt in gathering a correct solution. I will just put all my work that way anyone who looks at this can easily follow my path and be able to correct my work.
The Attempt at a Solution
Normal force on car = 1480(kg) * 9.81(m/s^2) = 14518.8(N)
Friction on car = 14518.8(N) * 0.15 = 2177.82(N)
Normal force on trailer = 300(kg) * 9.81(m/s^2) = 2943(N)
Friction on trailer = 2943(N) * 0.15 = 441.45(N)
3900(N) in my problem will be working in the positive direction as the other forces are resisting movement due to friction:
F = 3900(N) - 2177.82(N) - 441.45(N) => 1280.73(N)
Now, using Newton's 2nd law of F = m * a, I have rearranged to solve for acceleration:
a = F / m
a = 1280.73(N) / [1480(kg) + 300(kg)] =>0.7195(m/s^2)
F(trailer)=m(trailer) * a(trailer) + any other additional forces acting on the trailer?
F(trailer) = 300(kg) * 0.7195(m/s^2) + 441.45(N) => 657.3(N)
660(N) is my solution.
Would anyone be kind enough to help correct my mistakes? I appreciate you taking the time to take a look!