Astr 2100 Descriptive Astronomy
Fall 2017 - Assignment 6
due Wednesday October 25th 2017

The answers to some of these questions can be quite involved. Please supply complete answers, including all your calculations, in case I need to assign partial credit.

 
  1. True or false?
    1. If you drive down a straight road at constant speed then the net force on you is zero
    2. A comet coming into the Solar System from the far reaches (beyond Pluto) speeds up towards the Sun because it is falling without any force acting on it.
  2. When a force F is applied to a mass M then the acceleration is 2 m/s². If a force 3F is applied to a mass 3M what is the acceleration?
  3. When a force F is applied to a mass M then the acceleration is 2 m/s². If a force 3F is applied to a mass ½M what is the acceleration?
  4. On the Earth (4000 miles from the center) your weight is 120 lbs. What would it be inside a rocket at a distance of 24,000 miles from the center (that is 20,000 miles above the surface)?
  5. On the Earth (4000 miles from the center) your weight is 120 lbs. How far (measured from the center of the Earth) would you have to go to have a weight of only 25 lbs?
  6. On the Earth your weight is 120 lbs. What would it be on the surface of a planet which has 12 times the mass and twice the radius?