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# why is the tension felt by the car and the trailer is the same by the same string? Watch

1. hello, why is the tension felt by the car and the trailer is the same by the same string when the car is towing the trailer?
I understand that there is tension pulling the trailer foward but why is there tension in the opposite direction also?
thank you
2. Newton's third law.

The force acting on the car from pulling the trailer equals the force acting on the trailer from being pulled by the car.

A rope is a hard thing to conceptualise. But think of a simpler bit equivalent scenario, a car pulling a trailer by a chain. Now apply Newton's third law to every adjacent pair of chain links, and you'll see how the (same) force - tension - is transmitted from the car to the trailer. A rope is essentially the same.
3. (Original post by mik1a)
Newton's third law.

The force acting on the car from pulling the trailer equals the force acting on the trailer from being pulled by the car.

A rope is a hard thing to conceptualise. But think of a simpler bit equivalent scenario, a car pulling a trailer by a chain. Now apply Newton's third law to every adjacent pair of chain links, and you'll see how the (same) force - tension - is transmitted from the car to the trailer. A rope is essentially the same.
Thank you so much for the reply
4. (Original post by anonymousdude24)
Thank you so much for the reply
You can also imagine an analogy of you pulling a suitcase. You pull the suitcase forwards, but you can also feel it pulling you back! So the same is true of the car.

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