Two uniform very long (infinite) rods with identical linear mass density rho do not intersect. Their directions form an angle α and their shortest separation is a. 1. Find the force of attraction between them due to Newton's law of gravity.
2. Give a dimensional argument to explain why the force is independent of a.
3. If the rods were of a large but finite length L, what dimensional form would the lowest order correction to the force you found in the first part have? Note: for ' J-n/2 1-42 sin2 θ 1-A