# Homework Help: Find the tension in the hitch when a car is towing a trailer

1. Sep 28, 2008

### lalalah

I think I basically get the gist of this problem, but I want to know wjether i did everything correctly.
So...

1. A car is towing a boat on a trailer. The driver starts from rest and accelerates to a velocity of +18.5 m/s in a time of 25 s. The combined mass of the boat and trailer is 562 kg. The frictional force acting on the trailer can be ignored. What is the tension in the hitch that connects the trailer to the car?

2. using a = v/t , m_u * FN = fk (this might be relevvant, but i didn't use it myself), sigmaFx = m2ax

3. The attempt at a solution

I simply multiplied the mass of the car and trailer by the acceleration found by dividing the velocity by time.
However, this is so simple of an approach that I feel doubts as to whether it is the correct measure:

sigma F = 562 kg * [(18.5 m/s)/(25 s)]
sigma F = 416 N???

is this right?

2. Sep 28, 2008

### PhanthomJay

Is the mass of the car given? The problem states the mass of the boat and trailer only. Your answer is correct only if you assume the car has negligible mass, which is a bit silly, so that's why i'm wondering if you left out something in the problem statement.

3. Sep 28, 2008

### lalalah

so it's correct? yay! the weight of the car is negligable

4. Sep 28, 2008

### PhanthomJay

Don't tell my beat up Chevy, you'll hurt its feelings.