Question

Why is the pulley rope tension equation on both sides here? Can someone explain it intuitively to me?

Answer 1

You're asking why there are two different fbd's? You have 2 different masses on opposite ends of the pulley system so they each need their own force equations

Answer 2

Do you use the Giancoli physics book?

The tension is on both sides because the rope is connected to both objects - both objects feel the pull of the rope.

If there was no tension in the rope on one of the objects, then... people die.

Answer 3

The tension on both sides is equal, because we're ignoring the pulley at the top and the weight of the rope, so the tension in the left side of the rope is equal to the right side.

Answer 4

oops, sorry guys i poofed
@agent0smith yeah I do use that book!!
Yeah i guess, aside from technical complications, I figured the tension is balanced because the system is in equilibrium. if it wasn't balanced, it'll want to be balanced and slide one object down and the other up until it is, or something like that. that's why if a force is applied to one side, like pulling the rope, it changes that balance and accelerates the system ahaha

Answer 5

@johnweldon1993 oh nah, I understand we're analyzing the forces on both objects here

Answer 6

Tension is equal on both sides as long you assume the rope ideal (massless, doesn't stretch), and you ignore the rotational inertia of the pulley.

Answer 7

The system is not in equilibrium btw - the weight of the elevator is greater than the counterweight.

Answer 8

@agent0smith does that mean that as the system accelerates T will remain constant?

Answer 9

@agent0smith does that mean that as the system accelerates T will remain constant?

Answer 10

Yes. None of the forces are changing as it accelerates. The only quantity changing is velocity.