1. A plastic ball with a mass of 3.5 kg moves in a circular path with a radius of 25 cm at a constant 2 revs/s. a. Find the period of the ball.
b. Calculate the linear speed of the rotating ball,.
c. Find the centripetal acceleration of the ball.
d. Draw a Free Body Diagram of the force acting on the ball.
e. Find the centripetal force acting on the ball.
2. Let’s analyze the spinning Earth whose radius is 6.38 x106 m and completes one spin each day. a. What is the speed of a person standing on the equator as the Earth rotates about its axis? b. What is the centripetal acceleration of the person?
c. If the person had a mass of 120 kg, what is the Centripetal force on the person?
3. A towel is placed in a washing machine to be washed. During the spin cycle, what is the direction of the Net Force acting on the towel?
4. What does every physical object in the known universe have in common?
5. Is the Force of Gravitation attractive or repulsive?
6. What can be said about the force of Gravitation between two bodies in terms of:
a. the magnitude?
b. the direction on each?
7. The force is directly proportional to the product of the _______________________.
8. The force is inversely proportional to the __________ _____________ of the distance between them.
9. According to the Law of Universal Gravitation…
a. The larger the masses, the ____________________ the force between two objects
b. The larger the distance, the ___________________ the force between two objects
10. Suppose that two objects attract each other with a gravitational force of 16 units. If the distance between the two objects is doubled, what is the new force of attraction between the two objects?
11. Suppose that two objects attract each other with a gravitational force of 16 units. If the distance between the two objects is reduced in half, then what is the new force of attraction between the two objects?
12. Calculate the gravitational force between the Earth (m=5.98 x 1024 kg) and a 10,000 kg satellite orbiting a distance of 1.28 x 107 m from the center of the Earth. 13. What factor determines how fast a body must be moving in order to stay in orbit?
14. Define Geosynchronous Orbit. What is the period of such an orbit?
15. Use Kepler’s Second Law. The diagram below shows the elliptical orbit of a planet with a period of 1300 days. If area I is equal to area IV, what day is it at point X?
16. Earth moves more slowly in its orbit during June than during January. Is Earth closer to the sun in June or in January? What is the rationale for your answer? 17. While at a distance of 8.303 x106 m from the center of the Earth, it takes a satellite 250 min to complete 2 orbits.
a. Find the period for the satellite.
b. Find the circumference of the satellites orbit.
c. Find the linear speed the satellite is traveling at in order to stay in orbit.
d. Determine the centripetal acceleration for the satellite.
18. Billy and Bobby Big Ball have been placed into outer space away from any other objects. Billy has a mass of 1000 kg and Bobby has a mass of 500 kg. They are a center to center distance of 1.5 m apart.
a. Draw a Free Body Diagram showing the Forces acting on Billy and Bobby.
b. Find the force of gravitational attraction that exists between Billy and Bobby.
19. For the Diagram below, draw the force and velocity vectors for the planet at each of the positions.