AP Physics Gravity Short Answer Test 1. Make a diagram showing the experimental set up used to first determine the value of the universal gravitational constant. 2. Explain how the experimental set up used to first determine the value of the universal gravitational constant operated and was used. 3. Show the step by step derivation of Kepler's Third Law of Planetary motion from the Law of Universal Gravitation and centripetal motion equations. 4. Explain where the base level for energy should be placed when trying to determine escape velocity and why it is placed at this point. 5. Show the step by step derivation of how escape velocity is found - neatness and completeness count. 6. Explain how and why epicycles were used to support the geocentric model of the universe.
1
-1 WRONG NUMBER OF SIGNIFICANT DIGITS -2 WRONG OR NO UNITS -1 WRONG OR NO SIGN WHERE NEEDED -1 ARITHMETIC ERROR MUST SHOW THE CALCULATIONS Unless stated, all problems ignore the effects of air resistance.
Be sure to include the correct number of significant digits (at least two with all answers) and to write all answers with the correct units. SHOW WORK ON ATTACHED PAGES FOR PARTIAL CREDIT.
AP Physics Gravity TEST
1 2 3 4 5 6 7 8 9 10 11 12
________________ ________________ ________________ ________________ ________________ ________________ ________________ ________________ ________________ ________________ ________________ ________________
13 14 15 16 17 18 19 20 21 22 23 24
________________ ________________ ________________ ________________ ________________ ________________ ________________ ________________ ________________ ________________ ________________ ________________
25 26 27 28 29 30 31 32 33 34 35 36
________________ ________________ ________________ ________________ ________________ ________________ ________________ ________________ ________________ ________________ ________________ ________________
WHAT TYPE OF RELATIONSHIP EXISTS 1. BETWEEN THE GRAVITATIONAL FORCE AND THE DISTANCE BETWEEN THE CENTERS OF TWO OBJECTS? 2
2. Write the formula for the Law of Universal Gravitation. M1 is the original size. M2 is the original size. The distance between the centers of each mass is changed to 0.25 R. 3. WHAT HAPPENS TO THE FORCE OF GRAVITY? M1 is the original size. M2 is the original size. The distance between the centers of each mass is changed to 4 R.
4. WHAT HAPPENS TO THE FORCE OF GRAVITY? M1 is the original size. M2 is CHANGED TO 3 TIMES the original size. The distance between the centers of each mass remains R. 5. WHAT HAPPENS TO THE FORCE OF GRAVITY? M1 is the original size. M2 is CHANGED TO 3 TIMES the original size. The distance between the centers of each mass changes to 4 R.
3
6. WHAT HAPPENS TO THE FORCE OF GRAVITY? M1 is changed to 1/9 the original size. M2 is CHANGED TO 5 TIMES the original size. The distance between the centers of each mass changes to 2/3 R.
7. WHAT HAPPENS TO THE FORCE OF GRAVITY? AN ASTEROID ORBITS THE SUN ONCE EVERY 25 YEARS WHILE THE EARTH (1 A.U. FROM THE SUN) TAKES ONE YEAR TO ORBIT THE SUN. 8. WHAT IS THE AVERAGE ORBITAL RADIUS OF THE ASTEROID? Give the answer in Astronomical Units (A.U.) 9. Determine the period (in years) of a second asteriod orbiting the sun with a mean orbital radius of 3.5 A.U. 10. A SATELLITE ORBITS THE EARTH ONCE A DAY. WHAT IS THE PERIOD (IN SECONDS) OF THE SATELLITE? Identify the term, person, career. social or political organization responsible 11. Person who developed the theory of a heliocentric universe which was to be widely accepted by Western Europe for over a thousand years. 12. Person who developed the law of universal gravitation. 13.. Type of person who used the positions of stars and planets to forecast the future.
4
14. Civilization which first relied on the positions of stars to predict flooding of the local river (the Nile river). 15. Predominant force (social institution) resisting the acceptance of the three laws of planetary motion. 16. The person who possessed the best astrological equipment and collected data of his time, which allowed his student to determine important astronomical relationships. 17. The civilization credited with the origination and development of the theory of a geocentric universe through thought rather than collection and examination of data. 18. Special type of motion exhibited by planets which required special explanations and additions to the circular orbits in which planets were thought to move 19. Ancient civilization where the process of science consisted mainly of the discussion of ideas rather than the gathering of data through experiments. 20. The individual who is credited with using a telescope to first view the moons of Jupiter. 21. The person who developed an experiment to gather experimental information to determine the value of G, the Universal Gravitational Constant. A ball of mass 3M moves with speed 10V toward a bat. The bat hits the ball and the ball leaves with speed 25V in the exact opposite direction with which it approached the bat. 22. What was the change in momentum of the ball? 23. What was the kinetic energy of the ball after being struck (in terms of M and V)? 24. A 5.52 kg bowling ball is carried 25.3 meters down a hallway without the height changing. How much work was done against gravity? An object of mass 2M starts from rest and has a variable force applied according to the equation F = a X + b X a time 4t. 25. What is the momentum at time 4t? 2 for
A small ball rolls with a velocity V off the edge of a table of height H a horizontal distance of 2D. 26. How far from the edge of the table does the ball land if the velocity is increased to 9V (answer in terms of D)?
5
A box of mass 2M slides along a frictionless surface with a velocity of 4V. It strikes a second box of mass 2M in a perfectly elastic collision. The second box moves forward and strikes a third box of 2M in a perfect inelastic collision.
27. What is the combined speed of the second and third box after the inelastic collision? 28. A woman runs up a flight of stairs with speed, V. The gain in her gravitational potential energy is U. If she runs up the same flight of stairs with half the speed (.5V), what will be her gain in gravitational potential energy? A power P is obtained from a motor according to W = 4t + 3t 2 . Where W is the work done and t the time. 29. When the motor starts from rest, what amount of power is produced at 3.0 seconds? A railroad car (mass 3M) filled with water (mass 2M) travels along a train track with a constant speed of 5V. A hole is opened in the bottom of the car allowing the water to flow out. 30. What is the speed of the car when no water remains in the car? Two objects of unequal mass approach each other head on with the same speed 2V. The object moving to the left has mass M, the object moving to the right has mass 4M. 31. What is the total kinetic energy of the system after an inelastic collision occurs?
6
A bullet of mass 2M is fired with a speed V and strikes a box of mass 8M. A perfectly inelastic collision occurs and the combined mass travels up and through a loop of radius R. 32. What is the minimum speed the bullet must have to propel the combined mass through the loop? (solve in terms of M, R and g) If an object is thrown into the air with a velocity of 12 m/s STRAIGHT UP. 33. What is the acceleration 1.0 seconds after reaching the apogee point? When a certain elastic band is stretched a distance X, it 2 exerts a restoring force of magnitude F = 2 X + 8 X 34. What is the work done by an outside agent is slowly changing the stretch from X = 3L to X = 5L ? A block of mass M is pushed against a spring, compressing it distance 3X. The spring is then released. The spring projects the block along a frictionless horizontal surface, giving the block a speed 2V. 35. If the spring is compressed 1/2 X what is the velocity of the block after it leaves the spring?
Place the answer under question 36 on the answer sheet. XC What is the acceleration due to gravity at the surface of the third planet from the sun?
7