Recent content by acr

Can you say Kepler's 3rd?

Isn't it E = - \frac{GMm}{2a} ? The virial theorem states that <E> = 1/2<U> and it can be shown that <U> = - \frac{GMm}{a}

Thanks again. Because r is the separation between m1 and m2, L would be m2r2 d theta/dt (choosing to let r represent the position of m2 relative to m1). When I use the result above for dt, the new integral ends up coming out as \frac{-Gm_1 m_2^2 a (1-e^2)^{1/2}}{L} Which would...

Thanks tiny-tim, I'm trying to make sense of how to incorporate the conservation of angular momentum. Would it be correct to assume that \textbf{v} \times \textbf{r} = r^2 \frac{d\theta}{dt}=const=\frac{L}{m} is a valid statement? This would indicate that dt=\frac{mr^2 }{L} d...

I think that F= \frac {kq_1 q_2} {r^2} so E=\frac{F}{q} = \frac{kq}{r^2} not \frac {k}{r^2} Right?

Hello, I'm trying to show that the time average of the potential energy of a 2-body system is equal to the instantaneous potential energy of that system when the two bodies are separated by a distance equal to the semi-major axis, a. So I know that U = \frac{-Gm_{1}m_{2}}{r} and the...