7Afinalreview - Physics 7A Final Review (by Pavan Hosur) 1...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Physics 7A Final Review (by Pavan Hosur) 1 Problems 1. Problem summary: A planet of mass m revolves around a star of mass M ( m ) in a circular orbit of radius R. A comet of mass m C ( m ) moving with a speed v C straight towards the star lands on the planet. Find the function r ( t ) (the radius as a function of time) that describes the new orbit. You may treat all objects as point masses. See if you can come up with a strategy to solve this. If not, read ahead. (a) First consider a more general situation: i. Show the following for a general orbit of any shape : E = 1 2 m r 2 + L 2 2 mr 2- GMm r where E is the total energy of the planet-star system and L is the angular momentum of the planet about the star. ii. What quantities are conserved in this motion? What is dE/dt ? Evaluate r in terms of r and the other constants. (Notation: x = dx/dt, x = d 2 x/dt 2 etc.) (b) Now return to the problem described above....
View Full Document

Page1 / 3

7Afinalreview - Physics 7A Final Review (by Pavan Hosur) 1...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online