Praxis General Science: Laws of Gravitation Chapter Exam

Exam Instructions:

Choose your answers to the questions and click 'Next' to see the next set of questions. You can skip questions if you would like and come back to them later with the yellow "Go To First Skipped Question" button. When you have completed the practice exam, a green submit button will appear. Click it to see your results. Good luck!

Page 1

Question 1 1. What is Newton's Law of Universal Gravitation in words?

Question 2 2. If all of the objects have around the same mass, which of the following objects has the most gravitational potential energy?

Question 3 3. A metal bar is positioned near the Sun. If the mass of the metal bar is 20,000 kilograms, the mass of the Sun is 2 x 10^30 kilograms, the distance to the nearside of the bar from the Sun is 100,000 meters, and the length of the bar is 300 meters, what is the force of gravity between the Sun and the bar?

Question 4 4. If the distance between two objects is doubled, and the mass of one of the objects is doubled, what happens to the gravitational force?

Question 5 5. What is Newton's Law of Gravitation?

Page 2

Question 6 6. Which of the following orbital eccentricities is NOT an elliptical orbit?

Question 7 7. If a planet's average distance from the sun is 10 AU, what is its orbital period?

Question 8 8. Which planet is the most eccentric in its orbit? (Not counting dwarf planets like Pluto.)

Question 9 9. If you increase the distance between two objects by a factor of three, what happens to the force between them?

Question 10 10. A 10 kg bowling ball is lifted from the ground to a height of 1 meter. Assuming the bowling alley is on Earth, how much gravitational potential energy does it now have?

Page 3

Question 11 11. Which of these describes the basic idea of how calculus is used to find the gravitational force due to an extended object?

Question 12 12. In general, what are Kepler's Laws?

Question 13 13. What is the eccentricity of a circular orbit?

Question 14 14. What is an elliptical orbit?

Question 15 15. Kepler's Second Law states:

Page 4

Question 16 16. The time it takes a planet to travel around the sun one time is known as the:

Question 17 17. Which of the following is an assumption of Newton's Universal Law of Gravitation that doesn't EVER apply to an extended object?

Question 18 18. What does eccentricity measure?

Question 19 19. What is the eccentricity of a parabolic trajectory?

Question 20 20. If a car is rolling naturally downhill without the engine running, what energy transfer is happening?

Page 5

Question 21 21. A planet is orbiting its star at a maximum radius of 1.2 x 10^7 meters. If the mass of the star is 2 x 10^30, and the current radius is 0.9 x 10^7 meters, what is the velocity of the orbit?

Question 22 22. Object A has a mass of 3 x 10^10 kilograms, and object B has a mass of 8 x 10^10 kilograms. If they are 8,000 meters apart, what is the gravitational attraction between them? (G = 6.67 x 10^-11)

Question 23 23. You lift a 3kg dumbbell from the ground until it is above your head, at a height of 1.5 meters. How much energy did you use in the process? (Assume that you're not a space alien, and your gym is on Earth.)

Question 24 24. A planet is orbiting its star at a maximum radius of 1.2 x 10^7 meters. If the mass of the star is 2 x 10^30, what is the time period of the orbit?

Question 25 25. How do we know that gravitational potential energy exists?

Page 6

Question 26 26. If the distance between the two foci in an orbit is 4 AU, and the length of the major axis is 9 AU, what is the eccentricity of the orbit?

Question 27 27. What is an extended object?

Question 28 28. If a planet's orbital period is 10 years, what is its average distance from the sun?

Question 29 29. A curve surrounding two points, called foci, such that the total distance from one focus to a point on the ellipse and back to the other focus is constant for every point on the curve is called:

Question 30 30. What kind of relationship does gravity follow with distance?

Praxis General Science: Laws of Gravitation Chapter Exam Instructions

Choose your answers to the questions and click 'Next' to see the next set of questions. You can skip questions if you would like and come back to them later with the yellow "Go To First Skipped Question" button. When you have completed the practice exam, a green submit button will appear. Click it to see your results. Good luck!

Praxis General Science (5435): Practice & Study Guide  /  Science Courses
Support