Kepler's laws, explanation of energetics and orbital motion

Question 1

What is Kepler’s 1st law?

Answer 1

Planets move in elliptical orbits, with the sun at one focus

Question 2

What is Kepler’s 2nd law?

Answer 2

A straight line from the planet to sun sweeps out equal areas in equal times

Question 3

What is Kepler’s 3rd law?

Answer 3

The cube of the mean orbital distance is proportional to the square of the time period of orbit

Question 4

What 2 equations do you make equal each other to prove Kepler’s third law?

Answer 4

The centripetal force and the gravitational force

mv^2 / R = GMm / R

mRw^2 = GMm / R w= 2 pi / T

Prove from there

Question 5

When an object is moving in a circular orbit, where does the force of gravity act, and what occurs as a result of this?

Answer 5

The force of gravity remains perpendicular to the velocity, so does no work on the comet so the comet has constant speed and KE

Question 6

Where is the bottom of the potential well?

Answer 6

At the surface of a planet

Question 7

What does the total energy of a spacecraft equal?

Answer 7

The gravitational potential energy + The kinetic energy