Winnetonka 9 th Grade Physics: Semester 2 Final Exam. Work Output Work Input. Efficiency = E! = mgh. g = 9.8 m/s/s. W = f x d P =!!

Transcription

1 Winnetonka 9 th Grade Physics: Semester 2 Final Exam Efficiency = Work Output Work Input E! = mgh E! = 0.5mv! g = 9.8 m/s/s W = f x d P =!!

2 1. A planet that has the conditions needed to sustain life is called a habitable planet. The factors that determine whether a planet is habitable include atmosphere, temperature, orbital path, magnetic field, mass- gravity, and location in solar system. Based on the data provided in the chart below, which characteristic is dependent upon the planet s mass- gravity? Mass- gravity Atmosphere Temperature Orbital range ( o C) Path Earth Intermediate YES 0 o 100 o Elliptical low eccentricity Moon Small None o to 101 o Elliptical low eccentricity Kepler 93 Large YES - 30 o to 150 o Elliptical low eccentricity Mercury Small None 450 o Elliptical low eccentricity Kepler 62 Intermediate YES - 80 o to 120 o Elliptical low eccentricity a. The chart shows that Atmosphere is dependent upon Mass- gravity since only bodies with intermediate or large Mass- gravity have atmospheres. b. The chart shows that Temperature is dependent upon Mass- gravity since small planets have high temperatures. c. The chart shows that Orbital path is dependent upon Mass- gravity since the orbital path varies with mass. d. The chart shows that no trait is dependent upon Mass- gravity.

3 2. Astronomers classify potential life supporting planets based on their temperatures. Determine the T- PHC for Earth if our planet s mean temperature is 70 o F. **Hint, convert a. Earth is a Class P planet. b. Earth is a Class M planet. c. Earth is a Class T planet. d. Earth is a Class ht planet.

4 Based on the chart above, which exoplanet is most similar to Mars? a. Gilese 581g b. Kepler - 62f c. HD40307 g d. Gilese 581d 4. Using the Moon Phases Chart shown, select the most likely date for the moon to be in the last quarter. a. February 10, 2013 b. April 18, 2013 c. July 29, 2013 d. September 8, 2013

5 5. Answer the Question at the right using the diagram below: The Moon orbits the Earth in about 27.3 days. Approximately how many days will it take for the Moon to move in its orbit from position three to the position four? a. 15 days b. 20 days c days d. 3 days

6 6. The graphic above shows the tidal information for three coastal locations in the United States. Using only the information in the graphic, select the statement below that is most accurate based on the information in the graphic. a. The average high tide for the April 2013 in Cossett Beach is mostly near 4 feet. b. The shoreline of Cutler Naval Base is irregular causing large variations in daily high and low tides. c. The Gulf Shores area experiences one high tide per day. d. Cooler northern ocean waters contribute to larger variations in low and high tides.

7 COMING ATTRACTION: Orbital motion kepler laws 7. The quote shown above is from Timon of Athens, a play by William Shakespeare written in the1600 s. In the same century, the discoveries of Galileo, Copernicus, Brache and Kepler started the Scientific Revolution. William Shakespeare s reference to the moon is a literary reference to: a. The heliocentric model of the universe supported by Copernicus. b. The moon s nighttime glow is the reflection of light from the sun. c. The radiant energy that remains from the Moon s origin as a star. d. The growing crime rates in medieval societies. 8. Velocity versus time graphs for five objects is shown below. All axes have the same scale. Which graph below shows constant velocity?

8 9. The following is a position versus time graph for an object during a 5 second interval. Which one of the following graphs of velocity versus time would best represent the object s motion during the same time interval?

9 10. What is the total displacement of the little girl? A. The girl has a displacement of 10 m. B. The girl has a displacement of 20 m. C. The girl has a displacement of 9 m. D. The girl has a displacement of 3 m. 11. Select the motion diagram that shows an object that is accelerating.

10 12. The Velocity vs. time graph in Figure A above shows the velocity of four moving objects. Select the Roman numeral that shows an object that is accelerating AND getting faster: a. I b. II c. III d. IV 13. The Velocity vs. time graph in Figure A above shows the velocity of four moving objects. Select the Roman numeral that shows an object that moving at a constant speed: a. I b. II c. III d. IV

11 14. A ball is resting at the top of a ramp. As it rolls down the ramp, its position changes and speeds up. Select the velocity vs. time graph below that represents the ball s change in velocity. 15. Joe and Linda are jogging together at the same speed. Joe s mass is triple that of Linda s mass. Joe s momentum is Linda s momentum. a. half of b. triple c. same as d. not related too 16. A 1N bowling ball and a 9N beach ball are rolling along a level straight road. The balls have the same momentum. What physical information can you assume about the mass or motion of the bowling balls? a. The balls have the same velocity b. The beach ball moves faster c. The bowling ball moves faster d. The mass of the balls are the same 17. The law of conservation of momentum states that: a. The momentum of the system depends on the changes of the velocity b. In a closed or open system, the momentum of the system will be conserved c. In a closed system, the total momentum of the system will remain constant d. In a closed system, the total momentum of the system will change because the mass will change

12 18. Force due to gravity, or Weight, is calculated by a. Adding mass and the acceleration of gravity b. Squaring the acceleration of gravity. c. Multiplying mass and the acceleration of gravity. d. Multiplying mass by velocity. 19. A 10 kilogram object is moved from the moon to Earth. The mass of the object on Earth is: a. 10 Newtons b. 10 kilograms c. Less than 10 kilograms d. Less than 10 Newtons. 20. The Standard International (S.I.) unit for measuring acceleration is: a. Meters / second b. Kilogram c. Newton d. Meters / second /second 21. Two balls of equal volume are dropped at the same time from the same height. a. The ball with more mass will strike the ground first. b. The ball with less mass will strike the ground first. c. The balls will strike the ground at the same time regardless of their mass.

13 22. What is an example of Newton s First Law? a. Two buffalos push each other with equal amounts of force. b. A sled moves down a snowy hill picking up speed. c. A car hits a patch of ice. It cannot stop and hits another car. 23. What is the force of a car, when it has a mass of 1200 kg and an acceleration of 2 m/s? a N b. 600 N c N d. 0 N 24. On earth, all free falling objects accelerate downward at a rate of. A. 9.8 m/s B. 1.6 m/s/s C. 9.8 m/s/s D. None of the above 25. A rock whirled by string in a horizontal plane will follow a circular path. If the string breaks, the tendency of the rock is to: A. Continue to follow a circular path. B. Follow a straight line path. C. Increase its speed. D. Revolve in a smaller circle.

14 26. Examine the picture showing a ball being dropped from a cliff. Select the graph that represents the relationship between position and time for the freely falling ball. A. Position 0 Time B. Position 0 Time C. Position 0 Time

15 Two spheres A and B are projected at the same horizontal velocity off the edge of two different height shelves. The starting height of Sphere A is 2.0 meters, while the staring height of Sphere B is 1.0 meter. Both spheres have the same size and mass. 27. If both spheres leave the edge of the table at the same instant, sphere B will hit the ground: A. Before sphere A. B. After sphere A. C. At the same time as sphere A. D. There is not enough information to decide. 28. If both spheres leave the edge of the table at the same instant, sphere B hits the floor at the spot marked X. Sphere A will hit the floor: A. At some point between the edge of the table and X. B. At the same distance from the table as X. C. At some point past X. D. There is not enough information to decide.

16 29. The speed at which a launcher fires tennis balls is constant, but the angle between the launcher and the horizontal can be varied. As the angle is increased from 30 degrees to 45 degrees, the range of the tennis balls a. Increases b. Decreases c. Cannot be determined d. Remains the same 30. When force decreases, distance stays the same, work. a. Increases b. Decreases c. Stays the same 31. When distance decreases, force stays the same, work. a. Increases b. Decreases c. Stays the same

17 32. Use the diagram to the right to calculate the amount of work done. The displacement of the object is 5 m to the right. a. 50 J b J c. 100 J d J 33. Felix carries a 5 N suitcase up three flights of stairs (a total height of 5 m). Next, he uses a rope and pulley to lift the suitcase upward 10 more meters with a force of 5N. How much work does Felix do on his suitcase during this entire motion? a. 0 J b. 25 J c. 50 J d. 75 J 34. Pete fills drink orders for customers at a pizza restaurant. He fills a pitcher full of Cola, places it on the counter top and gives the 3.0- kg pitcher a 5 N forward push over a distance of 2 m to send it to a customer at the end of the counter. Calculate the work done by Pete on the pitcher during the 2 m push. a. 10 J b J c. 2.5 J d J 35. When work decreases, time stays the same, power. a. Increases b. Decreases c. Stays the same

18 36. When time decreases, work stays the same, power. a. Increases b. Decreases c. Stays the same 37. When work output decreases, total work input stays the same, the efficiency. a. Increases b. Decreases c. Stays the same 38. What is the percent efficiency of a machine that requires 40 J of total work input to do 20 J of output work? a. 0.5% b. 2% c. 50% d. 100% 39. A 50 kg ball and a 100 kg ball move to the right at the same constant speed. Select the statement below that describes how their kinetic energies compare. V V a. The smaller ball has twice the kinetic energy of the larger ball. b. The smaller ball has half the kinetic energy of the larger ball. c. The smaller ball has four times more kinetic energy than the larger ball. d. The smaller ball has four times less kinetic energy than the larger ball.

19 40. A black ball moves at to the right at twice the speed of a white ball. If the balls are the same mass, select the statement below that describes how their kinetic energies compare. V 2V a. The black ball has twice the kinetic energy of the white ball. b. The black ball has half the kinetic energy of the white ball. c. The black ball has four times more kinetic energy than the white ball. d. The black ball has four times less kinetic energy than the white ball. 41. A pair of skydivers jump from an airplane when the plane achieves an altitude of 10,000 feet. If Earl s gravitational potential energy is greater than Javon s immediately after they jump, select the statement that must be true. a. Earl and Javon have the same mass so their terminal velocities will be the same. b. Earl has more mass than Javon. c. Earl has less mass than Javon. d. Earl falls faster than Javon since he has more mass.

20 42. The path of a bouncing ball is shown above. The mass of the ball is 2 kg. If the initial height (h0) of the ball is 5 meters, select the most likely values for the Gravitational potential energy of the ball at h1 and h2. a. At h1, Eg = 100 joules At h2, Eg = 75 joules b. At h1, Eg = 150 joules At h2, Eg = 100 joules c. At h1, Eg = 50 joules At h2, Eg = 25 joules d. At h1, Eg = 100 joules At h2, Eg = 50 joules 43. A ball rests at the top of a 1 meter tall ramp. The 4 kilogram ball begins rolling down the ramp. If the ball and ramp are a closed system, what is the energy of the system? a joules b joules c. 392 joules d joules

21 44. A 20 Newton crate is lifted 8 meters above the floor. How much work was done on the crate? 8 meters a. 2.5 joules b. 40 joules c. 80 joules d. 160 joules Before After Weight of the crate = 20 Newtons 45. A 20 kilogram crate is lifted 8 meters above the floor. How much more gravitational potential energy does the crate have after it was lifted? 8 meters a. 1,568 joules b. 784 joules c. 160 joules d. 2.5 joules Before After Weight of the crate = 20 Kilograms

22 46. When fossil fuels are burned or food is digested, energy is released. a. Mechanical energy b. Thermal energy c. Chemical energy d. Molecular energy 47. The Earth s atmosphere and magnetic field deflects some of the Sun s electromagnetic energy. Select the electromagnetic wave frequencies that most commonly reach Earth s surface. a. Radio waves, gamma waves, visible light waves b. Cosmic ray waves, visible light waves, radio waves c. Visible light waves, radio waves, microwaves d. Radio waves, visible light waves 48. Electromagnetic waves with can cause damage to human tissues. a. Short wavelength, high frequency, high energy b. Short wavelength, low frequency, high energy c. Long wavelength, low frequency, high energy d. Long wavelength, high frequency, low energy

23 49. Which one of the waves above has the shortest wavelength? A. A B. B C. C D. D 50. Which one of the waves above has the lowest frequency? A. A B. B C. C D. D

24 51. The Sun and nuclear power plants on Earth both use nuclear reactions to create energy. Which of the following statements below are false? I. The Sun conducts nuclear fusion. II. The Sun conducts nuclear fission. III. Nuclear power plants conduct nuclear fusion. IV. Nuclear power plants conduct nuclear fission. A. I and III B. I and IV C. II and III D. II and IV 52. Where is the does the pendulum s energy distribution match the Energy Pie Chart at the right? A. At positions 1 and 5 B. At position 3 only C. At positions 2 and 4 D. At positions 2 and 5

25 53. Using the figure above to predict the gravitational and kinetic energy at position C? A. Half Kinetic energy and half Gravitational Potential energy B. All Gravitational Potential energy C. All Kinetic energy