# Calculate Tension Between Car and Trailer

• Thomas Hochkins
In summary, Thomas helped a student with a homework question. The student is stuck and needs help. Thomas provided a free body diagram and helped with the force balance equation for the trailer.

## Homework Equations

I have no idea how to start this question, I looked at my notes from class and the textbook but just can't figure out how to start it!

## The Attempt at a Solution

Any help would be greatly appreciated! Even if just to get started!Thanks
Thomas

Thanks, I have done that but this is as far as I can get before becoming stuck!

Write down the force balance equation for the trailer. Also, in your free body diagram, you are missing a force between the ground and the car.

Chet

Hi, thanks again for the help! I have added in a friction arrow for the car and one for the trailer (not sure how I forgot that!) but I'm not sure what you mean about a for balance equation for the trailer?

Thanks
Thomas

Thomas Hochkins said:
Hi, thanks again for the help! I have added in a friction arrow for the car and one for the trailer (not sure how I forgot that!) but I'm not sure what you mean about a for balance equation for the trailer?

Thanks
Thomas
It is unnecessary to include a friction arrow for the trailer because its tires are not driven; they are just idling. But including a friction arrow for the force the road exerts on the car is important. Which direction do you think this arrow is pointing?

Getting back to the trailer, if you focus on the trailer as a free body, what is(are) the horizontal force(s) acting on it?

Chet

I see, I have the arrow for the friction under the car pointing towards the trailer. As for the trailer, I think the forces acting on it are simply its weight due to gravity and the tension between the trailer and the car given that friction is unnecessary, is that right?

Thanks again, hopefully I will have an epiphany soon!
Thomas

Thomas Hochkins said:
I have the arrow for the friction under the car pointing towards the trailer.
A car engine is not a jet engine. If there were no friction between tyres and road, would the car go?
In your diagram, you show a forward force propelling the car, but there are two things wrong with it. It has the wrong value (it takes 60s to reach 9m/s) and it is drawn in the wrong place.

Thomas Hochkins said:
I see, I have the arrow for the friction under the car pointing towards the trailer.
This is not correct. As haruspex was alluding to in the previous post, the frictional force exerted by the road on the car tires is pointing forwards, in the direction that the car is moving. The tires are driven by the car engine, and they are pushing backwards on the road surface. The road surface, in turn, is pushing forward on the car. This is where haruspex was saying that the forward arrow should go.
As for the trailer, I think the forces acting on it are simply its weight due to gravity and the tension between the trailer and the car given that friction is unnecessary, is that right?

Yes. So, given this information, what is the horizontal force balance on the trailer?

Chet

You might be interested in Newtons classic equation : f = m * a
This would be involved in both solutions.

Thanks for your help, I got the problem sorted today!

Thanks
Thomas

## What is tension between a car and trailer?

The tension between a car and trailer is the force that is exerted on the connection between the two vehicles. It is the force that keeps the trailer attached to the car and helps to distribute the weight between the two vehicles.

## How is tension calculated between a car and trailer?

Tension is calculated by the weight of the trailer multiplied by the gravitational force. This is then divided by the distance between the rear axle of the car and the front axle of the trailer. This calculation gives the amount of tension in pounds or Newtons.

## Why is it important to calculate tension between a car and trailer?

Calculating tension is important because it helps to ensure that the trailer is properly attached to the car and that the weight is distributed evenly. This is crucial for safe and efficient towing, as too much or too little tension can cause accidents or damage to the vehicles.

## What factors can affect the tension between a car and trailer?

The weight of the trailer, the type of hitch used, the distance between the two vehicles, and the speed of the car can all affect the tension between a car and trailer. Other factors like road conditions, weather, and driving habits can also play a role in the tension between the two vehicles.

## Can tension between a car and trailer be adjusted?

Yes, tension can be adjusted by using a weight distribution hitch or by changing the position of the hitch on the car or trailer. It is important to adjust the tension to the recommended amount for the specific weight and type of trailer being towed.