$ 20

1. Forces and Motion Simple Machines Waves Energy $ 10 $ 10 $ 10 $ 10 $ 20 $ 20 $ 20 $ 20 $ 30 $ 30 $ 30 $ 30 $ 40 $ 40 $ 40 $ 40 $ 50 $ 50 $ 50 $ 50 Dallas ISD Science Department

2. Which factor would most likely cause a • communications satellite orbiting Earth to return to Earth from its orbit? • F An increase in the satellite’s forward • momentum • G An increase in solar energy striking the • satellite • H A decrease in the satellite’s size • J A decrease in the satellite’s velocity Dallas ISD Science Department

3. J A decrease in the satellite’s velocity Dallas ISD Science Department

4. The weight lifter used a force of 980 N to raise the barbell over her head in 5.21 seconds. Approximately how much work did she do in raising the barbell? • F 380 J • G 982 J • H 2,000 J • J 10,000 J Dallas ISD Science Department

5. H 2,000 J Dallas ISD Science Department

6. A mechanic used a hydraulic lift to raise a • 12,054 N car 1.89 m above the floor of a garage. It took 4.75 s to raise the car. What was the power output of the lift? • A 489 W • B 1815 W • C 4796 W • D 30,294 W Dallas ISD Science Department

7. C 4796 W Dallas ISD Science Department

8. According to this graph, what was the bicycle’s acceleration between 6 and 10 seconds? • A 0.0 m/s 2 • B 0.65 m/s 2 • C 1.6 m/s 2 • D 6.5 m/s 2 Dallas ISD Science Department

9. A 0.0 m/s 2 Dallas ISD Science Department

10. These data were gathered by four groups of students. Each group performed four trials to determine • the acceleration rate of a toy car. Which group had the most-consistent data? • F Group Q • G Group R • H Group S • J Group T Dallas ISD Science Department

11. J Group T Dallas ISD Science Department

12. What is the efficiency of a pulley system if • 25% of the energy applied to the system is • converted to heat? • A 100% • B 75% • C 50% • D 25% Dallas ISD Science Department

13. B 75% Dallas ISD Science Department

14. Which lever arrangement requires the least effort force to raise a 500 N resistance? Dallas ISD Science Department

15. F Dallas ISD Science Department

16. What is the efficiency of an air conditioner if • there is a work input of 320 J and a work • output of 80 J? • F 4% • G 25% • H 240% • J 400% Dallas ISD Science Department

17. G 25% Dallas ISD Science Department

18. The space shuttle orbits Earth at approximately 8000 m/s. The shuttle stays in orbit because the — A shuttle’s action is balanced by Earth’s equal and opposite reaction B combination of gravity and the shuttle’s inertia creates a curved path parallel to Earth’s surface C net gravitational force is zero at the shuttle’s distance from Earth’s center D force of Earth’s gravity pulls the shuttle downward and the force of the moon’s gravity pulls the shuttle upward Dallas ISD Science Department

19. B combination of gravity and the shuttle’s inertia creates a curved path parallel to Earth’s surface Dallas ISD Science Department

20. A catapult was designed to project a small metal ball at a target. The resulting data are shown in the table. Which of these might explain the difference between the calculated and actual distances? A The ball landed short of the calculated distance because of an increase in momentum. B Air resistance caused the ball to land short of the calculated distance. C Initial mass of the ball changed with each trial. D The metal ball was too small for accurate measurements to be made. Dallas ISD Science Department

21. B Air resistance caused the ball to land short of the calculated distance. Dallas ISD Science Department

22. The pitch of a sound made by plucking a guitar string is determined by the — A frequency of the vibration produced B strength of the plucking force C distance between the strings D shape of the guitar body Dallas ISD Science Department

23. A frequency of the vibration produced Dallas ISD Science Department

24. Which wave has the greatest velocity? Dallas ISD Science Department

25. B Dallas ISD Science Department

26. When trying to spear a fish in water, a person needs to take into account the way light bends as it moves from water into air. The bending of light as it passes from one medium into another is known as — • F reflection • G refraction • H diffraction • J polarization Dallas ISD Science Department

27. G refraction Dallas ISD Science Department

28. When white light passes through a triangular block of glass or a prism, the light that comes through is a rainbow of colored light: red, orange, yellow, green, blue, and violet. The colors are the result of the refraction, or bending of the beam of white light, and provide evidence that white light is a combination of all the colors. The colors spread out into a spectrum or rainbow because the amount of refraction that occurs depends on the wavelength, and each color has a different wavelength. The wavelength of red is the longest, and the wavelength of violet is the shortest. The shorter the wavelength, the greater the amount of refraction. Thus, violet is refracted the most and red is refracted the least. • Based on the statement above, what is the sequence of the colors yellow, violet, and red when they are arranged in increasing order of the amount of refraction each color undergoes when it passes through a prism? • A. yellow, red, violet • B. violet, yellow, red • C. red, violet, yellow • D. red, yellow, violet Dallas ISD Science Department

29. D.red, yellow, violet Dallas ISD Science Department

30. The reflection of waves from a surface follows which of the following rules? • None of the energy carried by the wave is reflected. • The angle of incidence is always normal to the surface. • The angle of incidence is equal to the angle of reflection. • Only light waves polarized in the horizontal direction are reflected. Dallas ISD Science Department

31. C. The angle of incidence is equal to the angle of reflection. Dallas ISD Science Department

32. The moon’s surface becomes hot during the long lunar day because the sun transfers heat to the moon. This heat transfer is accomplished almost entirely through theprocess of — • F convection • G refraction • H conduction • J radiation Dallas ISD Science Department

33. J radiation Dallas ISD Science Department

34. Battery-powered cars produce less airpollution than gasoline-powered cars. However, one environmental concern of using battery-powered cars is that batteries — A are heavier than gasoline engines B waste more energy than gasoline engines C contain toxic substances that are difficult to dispose of D produce direct current rather than alternating current Dallas ISD Science Department

35. C contain toxic substances that are difficult to dispose of Dallas ISD Science Department

36. Assuming the chart contains all energy transformations in the Earth system, how much solar radiation goes toward evaporating water? • F 40,000 terajoules • G 92,410 terajoules • H 121,410 terajoules • J 133,410 terajoules Dallas ISD Science Department

37. F 40,000 terajoules Dallas ISD Science Department

38. In which container is the substance unable to transfer heat by convection? Dallas ISD Science Department

39. J Aluminum Dallas ISD Science Department

40. Why is the sum of the products’ energy in this reaction less than the sum of the reactants’ • energy? • A Energy is given off as heat. • B The products absorb available energy. • C Energy is trapped in the reactants. • D The reactants’ energy is less than the • melting point of glucose. Dallas ISD Science Department

41. A Energy is given off as heat. Dallas ISD Science Department