Recent content by physicshelppls

Well it has to be either the change in heat or the change in temperature. Or is it a mixture of both? I'm trying to find an expression but most of them deal with the mass of the object.

Okay, so how would I find the heat in? Where do I go from here?

Is the heat going in not the same every cycle?

If the system starts at A and then returns to A that would mean everything goes back to how it started, right? Does that mean the work out would be the work in? I'm unsure.

ΔU is change in energy, in this case thermal energy. Q is heat added to the system. W is the work done.

Then ΔU is just equal to Q + W? I don't know what to say. And I was asking if it's the difference in either heat or difference in temperature, but I guess it's not. I'm really new to thermodynamics so I'm not sure how to answer these questions. Sorry. Edit: I tried ot take the difference...

Is it the difference in heat/temperature?

Sorry for the late reply. I know I need to find the heat input per cycle, that's the homework question. By first law do you mean ΔU = Q + W?

Homework Statement An inventor claims to have developed a device with the following properties: net work output per cycle = 20,000 J heat output per cycle = 50,000 J high temperature = 450 C low temperature = 160 C Calculate the heat input per cycle. Homework Equations ΔETH = W + Q efficiency...

Oh wow, I feel dumb for not even noticing that. So does the length of the vine not matter in finding the height? 9.8h = 1/2(6)2 and I just solve for h to get the answer to the first part?

Homework Statement Tarzan runs at 6 m/s and grabs a vertical vine (negligible mass) of length 4.1 m which is tied to a branch at the top. Tarzan then swings up. Determine the maximum height Tarzan will swing up and the maximum angle the vine will make with respect to vertical. Homework...