Recent content by PhysStudent81

So strange that for such seemingly simple problem there is no closed form result for r(t). t(r) is actually all I wanted so that's ok!

oh my goodness thank you. Rob

Homework Statement I have two masses of finite width, m_1 and m_2. The force is Newton's gravity, so U = k/r. I want to work out their relevant equations of motions r_1(t) and r_2(t) as they start off from rest and collide. I don't want to consider any rotational motion. Homework...

Thanks - I thought you were envisaging some kind of capacitor and was totally bemused by what you were suggesting. Totally see what you're saying now. Thanks

Why do you make this approximation? What's a binding post anyway?

Interesting Question: perhaps you could model it like two parallel plates 10cm apart i.e. a parallel plate capacitor. Q = CV and C = Area*epsilon/spacing = 0.1*epsilon (for a So Q = 1000*0.1*epsilon = 100*epsilon Should be easy turn amount of charge into a time given the amps.

Ok thanks both of you. I wanted to check whether I was missing something but I wasn't. It was a typo - setting the first current to 0.91mA gives the answer in the back of the book.

Homework Statement Power supply of EMF = E and internal resistance of R. Need E and R. This is connected to resistor of 10'000 Ohm. The current drawn from the power supply is 0.91A. A voltmeter of internal resistance 10'000 Ohm is connected in parallel to the resistor. The voltmeter reads...