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Energy

Energy. Work. Kinetic Energy. Potential Energy. Conservation of Energy. Physics is Phun!. Work. Kinetic Energy. Potential Energy. Conservation of Energy. Physics is Phun!. 5 pt. 5 pt. 5 pt. 5 pt. 5 pt. 10 pt. 10 pt. 10 pt. 10 pt. 10 pt. 15 pt. 15 pt. 15 pt. 15 pt. 15 pt.

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Energy

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  1. Energy

  2. Work

  3. Kinetic Energy

  4. Potential Energy

  5. Conservation of Energy

  6. Physics is Phun!

  7. Work Kinetic Energy Potential Energy Conservation of Energy Physics is Phun! 5 pt. 5 pt. 5 pt. 5 pt. 5 pt. 10 pt. 10 pt. 10 pt. 10 pt. 10 pt. 15 pt. 15 pt. 15 pt. 15 pt. 15 pt. 20 pt. 20 pt. 20 pt. 20 pt. 20 pt. 25 pt. 25 pt. 25 pt. 25 pt. 25 pt.

  8. 1-5 When energy is added to an object, what kind of work is done? A) positive B) negative C) zero D) not enough info 5 pt.

  9. 1-5A When energy is added to an object, what kind of work is done? A) positive 5 pt.

  10. 1-10 Is the work done on the object pictured below positive or negative? Force distance 10 pt.

  11. 1-10A Is the work done on the object pictured below positive or negative? Force distance Zero, since the force and distance are at right angles. 10 pt.

  12. 1-15 How much work is done by a car’s engine when it pushes with a force of 1450 N through a distance of 200 meters? 15 pt.

  13. 1-15A How much work is done by a car’s engine when it pushes with a force of 1450 N through a distance of 200 meters? Work = Force x distance Work = (1450 N)(200 m) = 290,000 J 15 pt.

  14. 1-20 How many watts are expended when a 100-N person walks 3.5 meters up a flight of stairs in 14 seconds? 20 pt.

  15. 1-20A How many watts are expended when a 100-N person walks 3.5 meters up a flight of stairs in 14 seconds? Work = Force x distance Work = (100 N)(3.5 m) = 350 J Power = Work / Time Power = (350 J)/(14 sec) = 25 Watts 20 pt.

  16. 4-20A When jumping off of a 3m tall garage, the 90 kg jumper lands on a pile of leaves. How much work does the pile of leaves do on the jumper? 25 pt.

  17. 4-20A When jumping off of a 3m tall garage, the 90 kg jumper lands on a pile of leaves. How much work does the pile of leaves do on the jumper? W = ∆KE = -∆PEg = -mgh W = - 90kg * 10m/s2 * 3m W = -2700 J 25 pt.

  18. 2-5 Negative work is done on a rolling bowling ball. What happens to the kinetic energy of the ball? A) KE increases B) KE does not change C) KE decreases D) not enough info 5 pt.

  19. 2-5A Negative work is done on a rolling bowling ball. What happens to the kinetic energy of the ball? C) KE decreases 5 pt.

  20. 2-10 True or False: It is possible for an object to have a negative kinetic energy. 10 pt.

  21. 2-10A True or False: It is possible for an object to have a negative kinetic energy. False 10 pt.

  22. 2-15 What is the KE of a car with mass 1200-kg that is moving at 180-km/hr? 15 pt.

  23. 2-15A What is the KE of a car with mass 1200-kg that is moving at 180-km/hr? KE = 1/2mv2 180 km/hr = 50 m/s KE = 1/2 (1200 kg)(50 m/s)2 KE = 1,500,000 Joules 15 pt.

  24. 2-20 Two identical cars are traveling down the road -- one moving at twice the speed of the other. If both apply the brakes, what will happen? A) they both travel the same distance B) the faster car will move twice as far C) the faster car will move four times as far D) not enough info 20 pt.

  25. 2-20A Two identical cars are traveling down the road -- one moving at twice the speed of the other. If both apply the brakes, what will happen? C) the faster car will move four times as far 20 pt.

  26. 2-25 A rocket of mass 500-kg lifts off from Earth with a thrust of 10,000-N to an altitude of 12-kilometers. How fast is it moving when the engine shuts off? 25 pt.

  27. 2-25A A rocket of mass 500-kg lifts off from Earth with a thrust of 10,000-N to an altitude of 12-kilometers. How fast is it moving when the engine shuts off? Work = Change in Energy Fd = mgh + 1/2mv2 10,000*12,000 = 500*10*12,000+ 1/2 (500)v2 v = 490 m/s 25 pt.

  28. 3-5 How do you calculate gravitational potential energy (GPE)? 5 pt.

  29. 3-5A How do you calculate gravitational potential energy (GPE)? GPE = weight x height = mgh 5 pt.

  30. 3-10 What is the GPE of a 50-kg object placed at a height of 10 m? 10 pt.

  31. 3-10A What is the GPE of a 50-kg object placed at a height of 10 m? GPE = mgh = (50 kg)(10 m/s2)(10 m) GPE = 5,000 Joules 10 pt.

  32. 3-15 If 32J of work is done on a spring with a spring constant of 16, what is the average force applied to the spring? 15 pt.

  33. 3-15A If 32J of work is done on a spring with a spring constant of 16, what is the average force applied to the spring? W = DPES = 32J = Fd = Favgx PES = ½ kx2 32J = ½ kx2 x = 2m 32J = Favg*2 Favg = 16N 15 pt.

  34. 3-20 A spring is compressed 0.4m by a 24kg mass. The mass is removed and the spring is then stretched 0.8m. How much energy is now in the spring? 20 pt.

  35. 3-20A A spring is compressed 0.4m by a 24kg mass. The mass is removed and the spring is then stretched 0.8m. How much energy is now in the spring? F = kx 24kg * 10m/s2 = k * 0.4m k = 600 N/m PES = ½ kx2 PES = 192 J 20 pt.

  36. 3-25 Your Team may wager from 0-50 pts. You must make your wager BEFORE the Daily Double is revealed!!! 25 pt.

  37. 3-25A Daily Double Daily Double How much power does the engine of a 2300-kg elevator put out if it climbs through 38-m in one minute? GPE = (2300 kg)(10 m/s2)(38 m) = 874,000 J Power = GPE / Time = (874,000 J)/(60 sec) Power = 14,567 Watts Daily Double

  38. 4-5 If the universe began during the Big Bang 15 billion years ago with an energy of 516 gadzillion Joules, how much energy is there in the universe right now? 5 pt.

  39. 4-5A If the universe began during the Big Bang 15 billion years ago with an energy of 516 gadzillion Joules, how much energy is there in the universe right now? 516 gadzillion Joules 5 pt.

  40. 4-10 When a car slows down to a stop where does all of its previous KE go? A) it turns into heat B) braking energy C) into total mechanical energy D) not enough info 10 pt.

  41. 4-10A • When a car slows down to a stop where does all of its previous KE go? • it turns into heat 10 pt.

  42. 4-15 When a diver who weighs 650-N jumps from a 10-m high diving platform, how much KE do they hit the water with? 15 pt.

  43. 4-15A When a diver who weighs 650-N jumps from a 10-m high diving platform, how much KE do they hit the water with? GPEinitial = KEfinal KEfinal = (650 N)(10 m) = 6500 J 15 pt.

  44. 4-20 When jumping up and down on a trampoline, the 450-N jumper leaves the trampoline with a KE of 3800 J. How high do they travel? 20 pt.

  45. 4-20A When jumping up and down on a trampoline, the 450-N jumper leaves the trampoline with a KE of 3800 J. How high do they travel? KEinitial = GPEfinal = mgh 3800 J = (450 N) h h = (3800 J)/(450 N) = 8.44 m 20 pt.

  46. 4-25 A 2-kg ball slides from rest down a 5-m tall incline as shown. When it is halfway down, how fast is it going? 25 pt.

  47. 4-25A A 2-kg ball slides from rest down a 5-m tall incline as shown. When it is halfway down, how fast is it going? GPEinitial = KE + GPE (2kg)(10m/s2)(5m) = 1/2 (2kg)v2 + (2kg)(10m/s2)(2.5m) 100 J = v2 + 50 J v = √(50) = 7.1 m/sec 25 pt.

  48. 5-5 What’s the anagram of the following phrase which is also the name of a famous actor of that movie genre? Old West Action 5 pt.

  49. 5-5A Old West Action Clint Eastwood 5 pt.

  50. 5-10 Name the character and movie that produced this famous quote: “A wizard is never late… he arrives precisely when he means to.” 10 pt.

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