Recent content by jtw2e

FOUND IT, finally... somehow the value I got for Resistance through the copper is wrong. Thanks for telling me I was on the right track so I knew it had to be a math error (or a programming error on their part).

Cannot find any math errors. Been on this for 5 hours and can't move on until I get it. :/

Current in wire -- Please help Homework Statement A 1.63-m length of wire is made by welding the end of a 100-cm long silver wire to the end of a 63-cm long copper wire. Each piece of wire is 1.1 mm in diameter. A potential difference of 5.0 mV is maintained between the ends of the 1.63-m...

How does that work? Because Power is Work / Time ... not KE/t right? I feel dumber every time I try. :/

... I can find that the angular acceleration \alpha = \omega/time = 1.9398 rad/s2. But I think that's an instantaneous acceleration. The only other thing I can think of is: Ffriction = I\alpha

It seems to me that whatever opposes rotation is the Ffriction. I guess it's a constant retarding force over the full 14.9s. But I don't really see how to tie it together. Would the retarding force be a torque?

Homework Statement A rotating uniform cylindrical platform that forms the base of carnival ride has a mass of 248 kg and radius of 4.8 m. The platform slows down from 4.6 rev/s to rest in 14.9 s when the motor is disconnected. Determine the power output required to maintain a steady...

While I would like to use CoE, we're supposed to find our answers with rotational constant acceleration approach. I've actually been doing my other homework with CoE just to get the answers turned in. I don't know how to find them with this rotational stuff.

Thank you. As of today we began rotational kinetic energy but did not get very much covered in the topic. We are supposed to begin torque on Friday.

Homework Statement Homework Equations ? constant acceleration equations I guess The Attempt at a Solution They didn't get to this part in class today, yet it's expected on our online homework due tonight. No idea how to even get started.

It's been...a very... long two weeks. ;) Thanks for putting up with my... frustration and confusion.

Sorry, the number should be 82.76km/hr (can't read my own writing). Even so, V = 82.76 km/hr / .5M It's still 1/2 times some number M. That number M is what I need to find V. Otherwise all I know is V = 165.5 / M

v=P/m = (88.76km/hr*MA)/(MA+MB) They don't all cancel. Only one of the masses cancels. You are left dividing by the other. Are my formulas in error?

Two unknowns: velocity and mass. Need a value to calculate either one. The fact that they are the same simplifies things, but I don't see how it gives me a number... such as 1500kg or 2000kg, etc...

Hi tiny-tim, I used strike to show that M/M = 1... i.e. those particular masses canceled. I have not found the V of the system after the collision, which is Ptotal/Masstotal. I haven't been able to find that value I don't know the mass of either car. So I'm stuck with Vfinal = (88.76km/hr)/MB...