PHYSICS F/SCI (LL) + MOD MAST ACC >BI<
4th Edition
ISBN: 9780134893365
Author: Knight
Publisher: PEARSON
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Textbook Question
Chapter 9, Problem 62EAP
62. When you ride a bicycle at constant speed, nearly all the energy you expend goes into the work you do against the drag force of the air. Model a cyclist as having cross-section area 0.45 m2 and, because the human body is not aerodynamically shaped, a drag coefficient of 0.90.
- What is the cyclist’s power output while riding at a steady 7.3 m/s (16 mph)?
Metabolic power is the rate at which your body “burns” fuel to power your activities. For many activities, your body is roughly 25% efficient at converting the chemical energy of food into mechanical energy. What is the cyclist’s metabolic power while cycling at 7.3 m/s?- The food calorie is equivalent to 4190 J. How many calories does the cyclist burn if he rides over level ground at 7.3 m/s for 1 h?
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PHYSICS F/SCI (LL) + MOD MAST ACC >BI<
Ch. 9 - If a particle’s speed increases by a factor of 3,...Ch. 9 - Prob. 2CQCh. 9 - 3. An elevator held by a single cable is ascending...Ch. 9 - The rope in FIGURE Q9.4 pulls the box to the left...Ch. 9 - 5. A 0.2 kg plastic cart and a 20 kg lead cart...Ch. 9 - A particle moving to the left is slowed by a force...Ch. 9 - 7. A particle moves in a vertical plane along the...Ch. 9 - 8. You need to raise a heavy block by pulling it...Ch. 9 - 9. A ball on a string travels once around a circle...Ch. 9 - A sprinter accelerates from rest. Is the work done...
Ch. 9 - 11. A Spring has an unstretched length of 10cm. It...Ch. 9 - 12. The left end of a spring is attached to a...Ch. 9 - The driver of a car traveling at 60 mph slams on...Ch. 9 - Prob. 14CQCh. 9 - Which has the larger kinetic energy, a 10 g bullet...Ch. 9 - At what speed does a 1000 kg compact car have the...Ch. 9 - 3. A mother has four times the mass of her young...Ch. 9 - 4. A horizontal rope with 15 N tension drags a 25...Ch. 9 - 5. A 25 kg box sliding to the left across a...Ch. 9 - A 2.0 kg book is lying on a 0.75-m-high table. You...Ch. 9 - Prob. 7EAPCh. 9 - Prob. 8EAPCh. 9 - 9. You throw a 5.5 g coin straight down at 4.0 m/s...Ch. 9 - Prob. 10EAPCh. 9 - 12. Evaluate the dot product if
and .
and .
Ch. 9 - 12. Evaluate the dot product if
and .
and .
Ch. 9 - 13. What is the angle ? between vectors and in...Ch. 9 - Prob. 14EAPCh. 9 - Prob. 15EAPCh. 9 - 16. A 25 kg air compressor is dragged up a rough...Ch. 9 - Prob. 17EAPCh. 9 - The two ropes seen in FIGURE EX9.18 are used to...Ch. 9 - 19. The three ropes shown in the bird’s-eye view...Ch. 9 - Prob. 20EAPCh. 9 - Prob. 21EAPCh. 9 - Prob. 22EAPCh. 9 - A particle moving on the x-axis experiences a...Ch. 9 - Prob. 24EAPCh. 9 - A horizontal spring with spring constant 750 N/m...Ch. 9 - 26. A 35-cm-long vertical spring has one end fixed...Ch. 9 - A 10-cm-long spring is attached to the ceiling....Ch. 9 - A 60 kg student is standing atop a spring in an...Ch. 9 -
29. A 5.0 kg mass hanging from a spring scale is...Ch. 9 - A horizontal spring with spring constant 85 N/m...Ch. 9 - 31. One mole (6.02 × 1023 atoms) of helium atoms...Ch. 9 - 32. A 55 kg softball player slides into second...Ch. 9 - A baggage handler throws a 15 kg suitcase along...Ch. 9 -
34. An 8.0 kg crate is pulled 5.0 m up a 30°...Ch. 9 - Justin, with a mass of 30 kg, is going down an...Ch. 9 - Prob. 36EAPCh. 9 - Prob. 37EAPCh. 9 - 38. How much energy is consumed by (a) a 1.2 kW...Ch. 9 - 39. At midday, solar energy strikes the earth with...Ch. 9 - Prob. 40EAPCh. 9 - Prob. 41EAPCh. 9 - Prob. 42EAPCh. 9 - 43. A 1000 kg elevator accelerates upward at 1.0...Ch. 9 - 44. a. Starting from rest, a crate of mass m is...Ch. 9 - Prob. 45EAPCh. 9 - 46. A particle of mass m moving along the x-axis...Ch. 9 -
47. A ball shot straight up with kinetic energy...Ch. 9 - 48. A pile driver lifts a 250 kg weight and then...Ch. 9 - Prob. 49EAPCh. 9 -
50. You’re fishing from a tall pier and have...Ch. 9 - Hook’s law describes an ideal spring. Many real...Ch. 9 -
52. The force acting on a particle is Fx =...Ch. 9 - 53. The gravitational attraction between two...Ch. 9 -
54. An electric dipole consists of two equal...Ch. 9 - Prob. 55EAPCh. 9 -
56. When a 65 kg cheerleader stands on a...Ch. 9 - Prob. 57EAPCh. 9 - Prob. 58EAPCh. 9 -
59. A horizontal spring with spring constant 250...Ch. 9 - 60. A 90 kg firefighter needs to climb the stairs...Ch. 9 - Prob. 61EAPCh. 9 - 62. When you ride a bicycle at constant speed,...Ch. 9 -
63. A farmer uses a tractor to pull a 150 kg...Ch. 9 - Prob. 64EAPCh. 9 - Prob. 65EAPCh. 9 - Prob. 66EAPCh. 9 - In problems 67 through 69 you are given the...Ch. 9 - Prob. 68EAPCh. 9 - Prob. 69EAPCh. 9 - Prob. 70EAPCh. 9 - Prob. 71EAPCh. 9 - Prob. 72EAP
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- a shopper in a supermarket pushes a cart with a force of 35 N directed at an angle of 25 below the horizontal. The force is just sufficient to overcome various frictional forces, so the cart moves at constant speed, (a) Find the work done by the shopper as she moves down a 50.0-m length aisle, (b) What is the net work done on the cart? Why? (c) The shopper goes down the next aisle, pushing horizontally and maintaining the same speed as before. If the work done by frictional forces doesnt change, would the shoppers applied force be larger, smaller, or the same? What about the work done on the cart by the shopper?arrow_forwarda shopper in a supermarket pushes a cart with a force of 35 N directed at an angle of 25 below the horizontal. The force is just sufficient to overcome various frictional forces, so the cart moves at constant speed, (a) Find the work done by the shopper as she moves down a 50.0-m length aisle, (b) What is the net work done on the cart? Why? (c) The shopper goes down the next aisle, pushing horizontally and maintaining the same speed as before. If the work done by frictional forces doesnt change, would the shoppers applied force be larger, smaller, or the same? What about the work done on the cart by the shopper?arrow_forward. In the annual Empire State Building race, contestants run up 1,575 steps to a height of 1,050 ft. In 2003, Australian Paul Crake completed the race in a record time of 9 min and 33 S, Mr., Crake weighed 143 lb (65 kg) , (a) How much work did Mr., Crake do in reaching the top of the building? (b) What was his average power output (in ft-lb/s and in hp)?arrow_forward
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