Recent content by kelseybrahe

I thought the same thing. I'll let you know what he says when I get the assignment back.

Gravity and/or some resistance force? Like the equal/opposite force? Or does acceleration or some kinetic force apply as well?

The same ticker tape. Which is why it's so confusing, because I didn't think you could do that?

Yeah, that makes sense and that's what we thought too. But the teacher said we had to use the same ticker tape to determine the friction on the cart. Or more, determine how it could be possible to find the friction acting on the cart.

It experiences friction from the string?

I'm not entirely sure. Perhaps the weight of the mass that pulls the cart and goes through the pulley? My physics teacher was away when I handed it in, but I talked to the other science faculty and they seemed to think that we were supposed to look at the distance between the dots on the...

Alright, cool. That makes sense. Thank you so much for all your help. You have saved me from so much stress. And I feel like I understand these things a bit better now. Thank you very much. So for the second (terribly worded) question I just talk about what I would do to find the friction...

It must have something to do with distinguishing the normal force of the cart from some total? Because if the normal force stays the same, you can always extract that from a total result. But what total? The total friction?

Sorry, missed this. Yes, that's right.

It depends on the type of materials the surfaces are made of? And their mass too? Oh, right. So, the friction acting on the cart will stay the same because it's mass doesn't change, but the friction acting on the pulley will vary as the mass of the weight varies. Is this because of the tension...

Yes, I think so. If the weight falls faster it will pull the cart faster too, but there will be greater friction on the pulley too, won't there? And the same if it falls slower. So the ratio would stay the same. But I'm not sure. it seems strange to say that things have an increase in...

Affect the acceleration of the cart? Well if you vary the mass of the weight pulling the cart, it will accelerate faster. If you reduce it, the cart will travel slower. The weight of the cart itself. Increase the weight and it will travel slower, reduce the weight and it will travel faster.

Well the pulley is controlling the speed that the accelerating mass falls, so that would affect the cart, right? So it must be friction on the cart?

Okay, thank you. This all makes sense. Okay, so the friction could be spread across the system in any way and the way I tried to isolate that was thus incorrect and wouldn't work at all. Alright, that seems really obvious now. Thank you. So contributing to the friction acting on the cart...

Is that a problem? Do I just ignore the negative sign? Oh. I assumed that I could use the same equation but narrow it down to find only the friction acting on the cart by swapping the numbers we used for the whole system to be only the numbers for the cart.