Universal Law of Gravitation

Objectives

After studying the material of this chapter, you should be able to:
1. Calculate the centripetal acceleration of a point mass in uniform circular motion given the radius of the circle and either the linear speed or the period of the motion.
2. Identify the force that is the cause of the centripetal acceleration and determine the direction of the acceleration vector.
3. Use Newton's laws of motion and the concept of centripetal acceleration to solve word problems.
4. Distinguish between centripetal acceleration and tangential acceleration.
5. State the relationship between the period of the motion and the frequency of rotation and express this relationship using a mathematical equation.
6. Write the equation for Newton's universal law of gravitation and explain the meaning of each symbol in the equation.
7. Determine the magnitude and direction of the gravitational field strength (g) at a distance r from a body of mass m.
8. Use Newton's second law of motion, the universal law of gravitation, and the concept of centripetal acceleration to solve problems involving the orbital motion of satellites.
9. Explain the "apparent" weightlessness of an astronaut in orbit.
10. State from memory Kepler's laws of planetary motion.
11. Use Kepler's third law to solve word problems involving planetary motion.
12. Use Newton's second law of motion, the universal law of gravitation, and the concept of centripetal acceleration to derive Kepler's third law.
13. Solve word problems related to Kepler's third law.
14. Identify the four forces that exist in nature.