Honors Physics Semester 2 Final Exam Review

Transcription

1 Honors Physics Semester 2 Final Exam Review 1600 kg 800 kg 9 m/s A truck with mass 1600 kg collides with a car with mass 800 kg at rest. They stick together and continue to move to the right. 1. What is the total momentum of the system before the collision? 2. What happens to the total momentum of the system after the collision? 3. What is the velocity of the pair after the collision 4. Compare the force of the truck on the car to the car on the truck during the collision. A 1.0 kg low-friction non-plunger cart is moving toward a 0.50 kg low-friction plunger. The carts collide and the spring is compressed and the carts momentarily come to a stop as shown. 5. How do the forces on each of the carts compare? 6. How do the accelerations of each of the carts compare? 7. How do the changes in momentum p of the carts compare? 8. Why is it safer for a pole-vaulter fall onto a puffy mat than onto the ground? 9. Is it possible for a bullet and a baseball to have the same momentum? 10. Why do you think medieval catapults had very long flinging arms? A Human Cannon Ball is a carnival trick where a person is launched from a giant cannon. Suppose that the person has a mass of 80 kg and the cannon a mass of 800 kg. When the daredevil is launched 11. Which exerts more force, the cannon on the man or the man on the cannon? 12. Based on mass which will have larger change in velocity the cannon or cannon ball? 13. If the cannon applies an average force of 1000 N to the man for 0.50 seconds, at what speed does the man leave the cannon? 14. At what speed does the cannon move backward?

2 Honors Physics Semester 2 Final Exam Review Page 2 Imagine that a steel ball is swung in a horizontal circle at a constant speed. 15. In what direction does the velocity of the ball point? E D C B 16. In what direction does the acceleration of the ball point? A 17. Are the forces balanced or unbalanced? How do you know? Top View 18. In what direction does the unbalanced force on the ball point?? 19. What is the nickname we give to the unbalanced force on the ball? What provides that unbalanced force? U6S0 20. What provides the outward force on the ball? 21. If you increased the force on the ball by a factor of three what would happen to the speed of the ball? 22. Look back at the original picture above. At the position shown the string breaks. Which path will the ball take? 23. Describe the path of the ball after the string breaks. To conduct a physics experiment we took some physics students and bicycles onto the high school track. The rider and bicycle have a total mass of 99 kg. On the bicycle he rode the 100 m turn in 8 seconds. The radius of the turn was 33 meters. 24. What is the average speed of the rider? 25. What is the centripetal force necessary for the runner to make the turn? 26. What provides the centripetal force necessary for the runner to make the turn? 27. In what direction must the runner lean to make the turn? 28. At what angle must the runner lean to make the turn? 29. What is the minimum coefficient of friction necessary for the runner to take the turn without slipping?

3 Honors Physics Semester 2 Final Exam Review Page As the Earth orbits the Sun, how many forces are on the Earth (ignore any forces by the moon)? 31. Where does the net (unbalanced) force on the Earth point? 32. If the Earth were twice as far from the Sun, the force of gravity on the Earth would be about 33. Which force is bigger the Earth on the Sun or the Sun on the Earth? F Earth on Sun = F Sun on Earth At the right is a picture of a comet moving in an elliptical orbit around a star. Assume that the comet moves from A to B to C. 34. At which of the locations in the orbit at the right is the force on the comet the greatest? The least? How do you know? F is the greatest at C and the least at A. The closer it is the greater the force. A B C 35. At which of the locations in the orbit at the right is the comet moving the fastest? The slowest? How do you know? The comet is the fastest at C and slowest at A. The closer it is the faster it is going. 36. Draw an arrow at each position that shows the force on the comet by the star? 37. Draw an arrow at each position that shows the velocity of the comet? 38. Define: U6S12 A Year the time it takes for the Earth to go around the sun once. A Day the time it takes for the Earth to spin around once. A Month the time it takes for the moon to go around the Earth once. Mercury is the closest planet to the sun. It has a mass of 3.30 x kg and a radius of 2.44 x 10 6 meters. 39. What is the acceleration due to gravity on Mercury? 3.8 m/s/s 40. What would be the gravitational force between a 200 kg astronaut and Mercury if he were standing on the surface? 760 N

4 Honors Physics Semester 2 Final Exam Review Page 4 Pictured below is a new roller coaster. A physics student riding and the coaster car have a combined mass of 200 kg. The car is at rest at point A and there is no braking at point D. Assume no friction between the coaster car and the track. A 125 m C 60 m B 15 m D 41. Rank the total energy from least to greatest. 42. Rank the gravitational energy from least to greatest. 43. Rank the kinetic energy from least to greatest. 44. Rank the speed of the cart from least to greatest. 45. What happens to the energy as the cart rolls from A to B? 46. Determine the student s gravitational energy at point A. 47. Determine the student s kinetic energy at point A. 48. At point B, her height is only 15 m. Determine her gravitational energy and kinetic energies at point B. 49. At point D the coaster is on the ground and still moving. How fast is it going at Point D? On a real rollercoaster friction (both from the track and the air) are very present. 50. Draw pie charts for a real rollercoaster as it moves from points A to B to C to D?

5 Honors Physics Semester 2 Final Exam Review Page 5 A crane lifts a steel girder of mass 1000 kg to a height of 45 meters. 51. Did the crane do work on the girder? How do you know? 1000 kg 52. How much work was done by the crane s motor? 53. If the motor pulls the girder up in 30 seconds what is the power output of the motor? 45 m k = 200 N/m m = 0.5 kg x = 0.20 m μ = 0.60 μ = 0 d = 1 m A 0.50 kg block that was being pushed against a spring is released from rest. The spring pushes the block which slides along a rough surface and then up a frictionless ramp and comes to a stop near the top of the ramp. 54. What happens to the total energy of the system as the block is pushed off of the spring; slides over the rough surface and then up the hill? 55. What is the speed of the block just after it leaves the spring? 56. What is the speed of the block as it leaves the rough surface? 57. To what vertical height does the block go? 58. Write one sentence that describes the spring constant. 59. What is the force that you would have to apply to hold the block against the spring?

6 Honors Physics Semester 2 Final Exam Review Page List 3 examples of longitudinal wave. 61. List 4 examples of transverse waves. A physics student shakes a slinky left and right so that waves are created. In the trial #1 she creates 2 waves every one second. In trial #2 she creates 6 waves every one second. In trial #3 the student pushed a slinky forward and back so that she creates 4 waves every one second. 62. Which is/are longitudinal waves? 63. Determine the frequency of trial #2. Trial Determine the wavelength of trial #2. Trial Determine the speed of the wave in trial #2? 66. Which (1 or 2) has the larger wavelength? Trial 3 6 m 67. Which trial (1 or 2) has the larger amplitude? In trial #3 above the slinky is pushed back and forth with a frequency of 4 waves/second. You then halved the frequency to 2 waves/second. 68. What would happen to the wavelength? 69. What would happen to the speed of the wave? 70. Bored and watching surfing on TV you notice the motion of the surfers waiting to catch a wave. How are they moving as they encounter the waves? The surfers go up and down! The waves are transverse so the vibration is perpendicular to the direction of motion

7 Honors Physics Semester 2 Final Exam Review Page 7 Two wave pulses on a slinky are moving toward each other as shown. 71. Draw a during picture for these wave pulses. 72. Draw an after for these wave pulses. 73. Watching a baseball game at Comerica Park from the outfield seats there is a noticeable delay between when you see the batter hit the ball and the crack of the bat. What s up with that? 74. With a stop watch you find the delay to be 0.5 seconds. How far away is the batter? The speed of sound is 340 m/s. A water bug is sitting on the surface of a pond when a frog jumps in and disturbs the water. The bug makes 5 bobs up and down in 20 seconds and reaches a maximum height of 0.20 meters above still water. With his handy-dandy meter stick, he measures the length between crests of the wave to be 2 meters. After a few seconds, the height of the waves is only 0.10 meters. 75. What is the period of the waves? 76. What is the frequency of the waves? 77. What is the speed of the waves in the water? 78. What happens to the speed of the wave as the amplitude becomes smaller?

8 Honors Physics Semester 2 Final Exam Review Page 8 Above are the regions of the electromagnetic Spectrum. 79. At you move left to right what happens to the frequencies? What happens to the wavelengths? U9S4 80. As you move left to right what happens to the speeds? What happens to the energies? U9S4 81. Why is it that radio waves can travel through space but sound waves cannot? U9S3 82. Compared the pitches of sounds made by long boom whackers to the pitches of sounds made by short boom whackers. Short instruments like violins produce higher pitched notes thank long instruments like cellos. 83. How do the frequencies of the higher notes compare to the lower notes. Banging a tuning fork harder produces a louder note. 84. How do the waves created by the louder note compare to a softer note?

9 Honors Physics Semester 2 Final Exam Review Page 9 Two charged metal spheres A and B are separated by a distance of 0.02 meters. Sphere A has a charge of +6.0 x 10-7 C and sphere B has a charge of +4.0 x 10-7 C. In addition, sphere B has twice the surface area as sphere A. 85. How will the spheres move if released? 86. Which supplies more force? 87. Calculate the force of A on B. A d = 0.02 m B 88. What happens to the force of A on B when the distance between the charged objects is cut in half?