a) Summarize the differences between the heliocentric and geocentric models of the Solar System. b) Describe which of Tycho Brahe's observations began to question the validity of Aristotle's statement that the heavens are 'perfect and immutable'.

Solution from part A: E=-KE = PE/2 Solution from part B: =3/2kt a. (NOTE: Treat the cloud as two equal masses interacting gravitationally across a distance equal to the radius of the cloud.) Use your result from part a to write down the condition for gravitational collapse in terms of the kinetic and potential energies (NOTE: This condition is an INEQUALITY)          b. Use your result from part b in order to replace the kinetic energy with its temperature equivalent in your expression for the collapse condition.          c. Solve the expression in ii above for the mass.

Need help, need to know if I'm doing this right

thank you for this explanation. however, i don't really see how it answers the question: does it match the reasoning?

Please answer the second question(everything in the bottom sentence.) please explain how you reached your answer.

Can you please explain part A more, I don't get why RA is smaller and RD is the bigger one

Please answer all these questions. Please make sure you're correct and double check your work. DO NOT SKIP ANY STEPS! PLEASE USE KEPLERS LAWS!

Subject: physics