College Physics: A Strategic Approach (4th Edition)
4th Edition
ISBN: 9780134609034
Author: Randall D. Knight (Professor Emeritus), Brian Jones, Stuart Field
Publisher: PEARSON
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Question
Chapter 11, Problem 56GP
a.
To determine
To find: The winner’s change in gravitational potential energy.
b.
To determine
To find: The total energy did the winner expand during the race.
c.
To determine
To find: The food Calories burned by the winner in the race.
d.
To determine
How many Calories are converted to thermal energy.
e.
To determine
To find: The winner’s
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The winning time for the 2005 annual race up 86 floors of the Empire State Building was 10 min and 49 s. The winner’s mass was 60 kg.a. If each floor was 3.7 m high, what was the winner’s change in gravitational potential energy?b. If the efficiency in climbing stairs is 25%, what total energy did the winner expend during the race?c. How many food Calories did the winner “burn” in the race?d. Of those Calories, how many were converted to thermal energy?e. What was the winner’s metabolic power in watts during the race up the stairs?
Question:
1. Suppose that the elevator is broken in the building n which you work and you
have to climb 9 stories.
-a height of 45m above ground level.
How many extra calories will this external work cost you if your mass is 70 kg and
your body work at 15% efficiency?
2. A 70 kg hiker climbed a mountain 1000 m high. He reached the peak in 3 hr.
A. Calculate the external work done by the climber.
B. Assuming the work was done at a steady rate during the 3 hr period.
Calculate the power generated durir
the climb.
C. Assuming the average O, consumption during he climb was 2 liters/min
(corresponding to 9.6 kcal/min), find the efficiency of the hiker's body.
D. How much energy appeared as heat in the body?
Championship swimmers take about 22 s and about 30 arm strokes to move through the water in a 50 m freestyle race.a. As shown, a swimmer’s metabolic power is 800 W. If the efficiency for swimming is 25%, how much energy is expended moving through the water in a 50 m race?b. If half the energy is used in arm motion and half in leg motion, what is the energy expenditure per arm stroke?c. Model the swimmer’s hand as a paddle. During one arm stroke, the paddle moves halfway around a 90-cm-radius circle. If all the swimmer’s forward propulsion during an arm stroke comes from the hand pushing on the water and none from the arm (somewhat of an oversimplification), what is the average force of the hand on the water?
Chapter 11 Solutions
College Physics: A Strategic Approach (4th Edition)
Ch. 11 - Rub your hands together vigorously. What happens?...Ch. 11 - Describe the energy transfers and transformations...Ch. 11 - According to Table 11.4, cycling at 15 km/h...Ch. 11 - Prob. 4CQCh. 11 - Prob. 5CQCh. 11 - For most automobiles, the number of miles per...Ch. 11 - Prob. 8CQCh. 11 - Prob. 9CQCh. 11 - Prob. 10CQCh. 11 - Prob. 11CQ
Ch. 11 - Prob. 12CQCh. 11 - For Questions 12 through 17, give a specific...Ch. 11 - For Questions 12 through 17, give a specific...Ch. 11 - For Questions 12 through 17, give a specific...Ch. 11 - For Questions 12 through 17, give a specific...Ch. 11 - For Questions 12 through 17, give a specific...Ch. 11 - For Questions 12 through 17, give a specific...Ch. 11 - Prob. 19CQCh. 11 - Prob. 20CQCh. 11 - Prob. 21CQCh. 11 - Prob. 22CQCh. 11 - Prob. 24CQCh. 11 - Prob. 25CQCh. 11 - Electric vehicles increase speed by using an...Ch. 11 - When the suns light hits the earth, the...Ch. 11 - Prob. 29CQCh. 11 - Prob. 30CQCh. 11 - Prob. 31CQCh. 11 - Prob. 32MCQCh. 11 - Prob. 33MCQCh. 11 - A person is walking on level ground at constant...Ch. 11 - A person walks 1 km, turns around, and runs back...Ch. 11 - 200 J of heat is added to two gases, each in a...Ch. 11 - Prob. 37MCQCh. 11 - A refrigerators freezer compartment is set at 10C;...Ch. 11 - A 10% efficient engine accelerates a 1500 kg car...Ch. 11 - Prob. 2PCh. 11 - A typical photovoltaic cell delivers 4.0 103 W of...Ch. 11 - Prob. 4PCh. 11 - Prob. 5PCh. 11 - Prob. 6PCh. 11 - In an average human, basic life processes require...Ch. 11 - Prob. 8PCh. 11 - An energy bar contains 22 g of carbohydrates. How...Ch. 11 - Prob. 10PCh. 11 - Prob. 11PCh. 11 - Prob. 12PCh. 11 - An energy bar contains 22 g of carbohydrates. If...Ch. 11 - Prob. 14PCh. 11 - Prob. 15PCh. 11 - Prob. 16PCh. 11 - The label on a candy bar says 400 Calories....Ch. 11 - Prob. 18PCh. 11 - A weightlifter curls a 30 kg bar, raising it each...Ch. 11 - Prob. 20PCh. 11 - Prob. 21PCh. 11 - Prob. 22PCh. 11 - Suppose your body was able to use the chemical...Ch. 11 - Prob. 24PCh. 11 - Prob. 25PCh. 11 - Prob. 26PCh. 11 - Prob. 27PCh. 11 - The planet Mercurys surface temperature varies...Ch. 11 - A piece of metal at 100C has its Celsius...Ch. 11 - Prob. 30PCh. 11 - 500 J of work are done on a system in a process...Ch. 11 - Prob. 32PCh. 11 - 600 J of heat energy are transferred to a system...Ch. 11 - 10 J of heat are removed from a gas sample while...Ch. 11 - A heat engine extracts 55 kJ from the hot...Ch. 11 - A heat engine does 20 J of work while exhausting...Ch. 11 - A power plant running at 35% efficiency generates...Ch. 11 - A heat engine operating between energy reservoirs...Ch. 11 - A newly proposed device for generating electricity...Ch. 11 - Prob. 41PCh. 11 - Prob. 42PCh. 11 - Prob. 43PCh. 11 - Prob. 44PCh. 11 - A refrigerator takes in 20 J of work and exhausts...Ch. 11 - Air conditioners are rated by their coefficient of...Ch. 11 - 50 J of work are done on a refrigerator with a...Ch. 11 - Prob. 48PCh. 11 - Find the maximum possible coefficient of...Ch. 11 - Prob. 50PCh. 11 - Prob. 51PCh. 11 - Prob. 52PCh. 11 - Prob. 53PCh. 11 - Prob. 55GPCh. 11 - Prob. 56GPCh. 11 - The record time for a Tour de France cyclist to...Ch. 11 - Championship swimmers take about 22 s and about 30...Ch. 11 - A 68 kg hiker walks at 5.0 km/h up a 7% slope....Ch. 11 - To make your workouts more productive, you can get...Ch. 11 - The resistance of an exercise bike is often...Ch. 11 - Prob. 62GPCh. 11 - Prob. 63GPCh. 11 - An engine does 10 J of work and exhausts 15 J of...Ch. 11 - An engine operating at maximum theoretical...Ch. 11 - An engineer claims to have measured the...Ch. 11 - A typical coal-fired power plant burns 300 metric...Ch. 11 - Prob. 68GPCh. 11 - Air conditioners sold in the United States are...Ch. 11 - The surface waters of tropical oceans are at a...Ch. 11 - The light energy that falls on a square meter of...Ch. 11 - Prob. 72MSPPCh. 11 - Prob. 73MSPPCh. 11 - Prob. 74MSPPCh. 11 - Prob. 75MSPPCh. 11 - Prob. 76MSPPCh. 11 - Prob. 77MSPPCh. 11 - Prob. 78MSPPCh. 11 - Prob. 79MSPP
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