# Gravitational potential of two equal stars

by benf.stokes
Tags: equal, gravitational, potential, stars
 P: 72 1. The problem statement, all variables and given/known data Two equal spherically symmetrical stars, A and B, each of mass M and radius r have their centers 6r apart. Make a sketch showing the lines on which the gravitational potential takes the values: 1. $$\frac{-10GM}{11r}$$ 2. $$\frac{-2GM}{3r}$$ 3. $$\frac{-GM}{3r}$$ Accurate plotting is not required but the general shape of the lines must be clear 4. What is the minimum velocity with which gas can be emitted from the surface of B and still be captured by A? Ignore any effects due to the motion of the stars 2. Relevant equations U = $$\frac{-GM}{R}$$ 3. The attempt at a solution I can't even get started. Thanks
 HW Helper Thanks P: 10,511 You can calculate the equipotential curves, but it was not required. For r=1, the equation for these curves is : $$\frac{1}{\sqrt{(x+3)^2+y^2}}+\frac{1}{\sqrt{(x-3)^2+y^2}}=C$$ But it is not easy to plot them. ehild