Physics
Physics
3rd Edition
ISBN: 9780073512150
Author: Alan Giambattista, Betty Richardson, Robert C. Richardson Dr.
Publisher: McGraw-Hill Education
bartleby

Concept explainers

bartleby

Videos

Question
Book Icon
Chapter 6, Problem 112P

(a)

To determine

The average power required for the person to hike up to the top of Yosemite Falls in 1.5h.

(a)

Expert Solution
Check Mark

Answer to Problem 112P

The average power required for the person to hike up to the top of Yosemite Falls in 1.5h is 94W_.

Explanation of Solution

Given that the mass of the person is 70kg, the height of Yosemite Falls is 740m, and the time is 1.5h.

Write the expression for the average power output.

Pav=ΔEΔt (I)

Here, Pav is the average power output, ΔE is the change in energy, and Δt is the time interval.

In the climbing process, the change in energy is equal to the change in gravitational potential energy. Hence the equation (I) can be modified by replacing ΔE by ΔU which is the change in gravitational potential energy.

Pav=ΔUΔt (II)

Write the expression for the change in gravitational potential energy.

ΔU=mgΔy (III)

Here, m is the mass, g is the acceleration due to gravity, and Δy is the change in height.

Use equation (III) in (II).

Pav=mgΔyΔt (IV)

Conclusion:

Substitute 70kg for m, 9.80m/s2 for g, 740m for Δy, and 1.5h for Δt in equation (IV) to find Pav.

Pav=(70kg)(9.80m/s2)(740m)1.5h=(70kg)(9.80m/s2)(740m)1.5h×3600s1h=94W

Therefore, the average power required for the person to hike up to the top of Yosemite Falls in 1.5h is 94W_.

(b)

To determine

The chemical energy used in hiking to the top of the Yosemite Falls in 1.5h.

(b)

Expert Solution
Check Mark

Answer to Problem 112P

The chemical energy used in hiking to the top of the Yosemite Falls in 1.5h is 2.0MJ_.

Explanation of Solution

Given that the human body is only 25% efficient in converting chemical energy to mechanical energy. Thus, it takes 4.0units of chemical energy for every single unit of potential energy gained by the body.

Upon hiking to the top of the Yosemite Falls, the body of the person gains potential energy.

Write the expression for the chemical energy used while gaining potential energy.

Echem=4.0ΔU (V)

Here, Echem is the chemical energy.

Use equation (III) in (V).

Echem=4.0mgΔy (VI)

Conclusion:

Substitute 70kg for m, 9.80m/s2 for g, and 740m for Δy in equation (VI) to find Echem.

Echem=4.0(70kg)(9.80m/s2)(740m)=2.0×106J=2.0×106J×1MJ1,000,000J=2.0MJ

Therefore, the chemical energy used in hiking to the top of the Yosemite Falls in 1.5h is 2.0MJ_.

(c)

To determine

The amount of energy used in kilocalories for the hike.

(c)

Expert Solution
Check Mark

Answer to Problem 112P

The amount of energy used in kilocalories for the hike is 490kcal_.

Explanation of Solution

Given that the chemical energy used for the hike is 2.0×106J.

Write the conversion formula between energy in Joules and kilocalories.

1kcal=4186J (VII)

The chemical energy used in the hike is given by the expression,

Echem=4.0mgΔy

Use the conversion formula (VII) to convert the Echem to kilocalories.

E(kcal)=Echem×1kcal4186J=4.0mgΔy×1kcal4186J (VIII)

Conclusion:

Substitute 70kg for m, 9.80m/s2 for g, and 740m for Δy in equation (VIII) to find E(kcal).

E(kcal)=4.0(70kg)(9.80m/s2)(740m)×1kcal4186J=485kcal490kcal

Therefore, the amount of energy used in kilocalories for the hike is 490kcal_.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!

Chapter 6 Solutions

Physics

Ch. 6.4 - Prob. 6.6PPCh. 6.5 - Prob. 6.5CPCh. 6.5 - Prob. 6.7PPCh. 6.5 - Prob. 6.8PPCh. 6.6 - Prob. 6.9PPCh. 6.6 - Prob. 6.10PPCh. 6.7 - Prob. 6.7CPCh. 6.7 - Practice Problem 6.11 A Misfire The same dart gun...Ch. 6.7 - Prob. 6.12PPCh. 6.8 - Prob. 6.13PPCh. 6.8 - Prob. 6.14PPCh. 6 - Prob. 1CQCh. 6 - Prob. 2CQCh. 6 - Prob. 3CQCh. 6 - Prob. 4CQCh. 6 - Prob. 5CQCh. 6 - Prob. 6CQCh. 6 - Prob. 7CQCh. 6 - Prob. 8CQCh. 6 - Prob. 9CQCh. 6 - Prob. 10CQCh. 6 - Prob. 11CQCh. 6 - Prob. 12CQCh. 6 - Prob. 13CQCh. 6 - Prob. 1MCQCh. 6 - 2. If a kangaroo on Earth can jump from a standing...Ch. 6 - Prob. 3MCQCh. 6 - Prob. 4MCQCh. 6 - Prob. 5MCQCh. 6 - Prob. 6MCQCh. 6 - Prob. 7MCQCh. 6 - Prob. 8MCQCh. 6 - Prob. 9MCQCh. 6 - Questions 9 and 10. A simple catapult, consisting...Ch. 6 - Prob. 11MCQCh. 6 - Prob. 1PCh. 6 - Prob. 2PCh. 6 - Prob. 3PCh. 6 - Prob. 4PCh. 6 - Prob. 5PCh. 6 - Prob. 6PCh. 6 - Prob. 7PCh. 6 - Prob. 8PCh. 6 - Prob. 9PCh. 6 - Prob. 10PCh. 6 - Prob. 11PCh. 6 - Prob. 12PCh. 6 - Prob. 13PCh. 6 - Prob. 14PCh. 6 - Prob. 15PCh. 6 - Prob. 16PCh. 6 - Prob. 17PCh. 6 - Prob. 18PCh. 6 - Prob. 19PCh. 6 - Prob. 20PCh. 6 - Prob. 21PCh. 6 - Prob. 22PCh. 6 - Prob. 23PCh. 6 - Prob. 24PCh. 6 - Prob. 25PCh. 6 - Prob. 26PCh. 6 - Prob. 27PCh. 6 - Prob. 28PCh. 6 - Problems 29–32. A skier passes through points A–E...Ch. 6 - Prob. 30PCh. 6 - Prob. 31PCh. 6 - Prob. 32PCh. 6 - Prob. 33PCh. 6 - Prob. 34PCh. 6 - 35. Emil is tossing an orange of mass 0.30 kg into...Ch. 6 - Prob. 36PCh. 6 - 37. An arrangement of two pulleys, as shown in the...Ch. 6 - Prob. 38PCh. 6 - Prob. 39PCh. 6 - Prob. 40PCh. 6 - Prob. 41PCh. 6 - Prob. 42PCh. 6 - Prob. 43PCh. 6 - Prob. 44PCh. 6 - Prob. 45PCh. 6 - Prob. 46PCh. 6 - 47. Refer to Problems 11-14. Find conservation of...Ch. 6 - Prob. 48PCh. 6 - Prob. 49PCh. 6 - Prob. 50PCh. 6 - Prob. 51PCh. 6 - Prob. 52PCh. 6 - 53. What is the minimum speed with which a meteor...Ch. 6 - 54. A projectile with mass of 500 kg is launched...Ch. 6 - Prob. 55PCh. 6 - Prob. 56PCh. 6 - Prob. 57PCh. 6 - Prob. 58PCh. 6 - Prob. 59PCh. 6 - Prob. 60PCh. 6 - Prob. 61PCh. 6 - Prob. 62PCh. 6 - Prob. 63PCh. 6 - Prob. 64PCh. 6 - Prob. 65PCh. 6 - Prob. 66PCh. 6 - Prob. 67PCh. 6 - Prob. 68PCh. 6 - Prob. 69PCh. 6 - Prob. 70PCh. 6 - Prob. 71PCh. 6 - Prob. 72PCh. 6 - Prob. 73PCh. 6 - Prob. 74PCh. 6 - Prob. 75PCh. 6 - Prob. 76PCh. 6 - Prob. 77PCh. 6 - Prob. 78PCh. 6 - Prob. 79PCh. 6 - Prob. 80PCh. 6 - Prob. 81PCh. 6 - Prob. 82PCh. 6 - Prob. 83PCh. 6 - Prob. 84PCh. 6 - Prob. 85PCh. 6 - Prob. 86PCh. 6 - Prob. 87PCh. 6 - Prob. 88PCh. 6 - Prob. 89PCh. 6 - Prob. 90PCh. 6 - Prob. 91PCh. 6 - Prob. 92PCh. 6 - Prob. 93PCh. 6 - Prob. 94PCh. 6 - Prob. 95PCh. 6 - Prob. 96PCh. 6 - Prob. 97PCh. 6 - Prob. 98PCh. 6 - Prob. 99PCh. 6 - Prob. 100PCh. 6 - Prob. 101PCh. 6 - Prob. 102PCh. 6 - Prob. 103PCh. 6 - Prob. 104PCh. 6 - Prob. 105PCh. 6 - Prob. 106PCh. 6 - Prob. 107PCh. 6 - Prob. 108PCh. 6 - Prob. 109PCh. 6 - Prob. 110PCh. 6 - Prob. 111PCh. 6 - Prob. 112PCh. 6 - Prob. 113PCh. 6 - Prob. 114PCh. 6 - Prob. 115PCh. 6 - Prob. 116PCh. 6 - Prob. 117PCh. 6 - Prob. 118PCh. 6 - Prob. 119PCh. 6 - Prob. 120PCh. 6 - Prob. 121PCh. 6 - Prob. 122PCh. 6 - Prob. 123PCh. 6 - Prob. 124PCh. 6 - Prob. 125PCh. 6 - Prob. 126PCh. 6 - Prob. 127PCh. 6 - Prob. 128PCh. 6 - Prob. 129PCh. 6 - Prob. 130PCh. 6 - Prob. 131PCh. 6 - Prob. 132PCh. 6 - Prob. 133PCh. 6 - Prob. 134PCh. 6 - Prob. 135PCh. 6 - Prob. 136PCh. 6 - Prob. 137PCh. 6 - Prob. 138P
Knowledge Booster
Background pattern image
Physics
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.
Recommended textbooks for you
Text book image
College Physics
Physics
ISBN:9781305952300
Author:Raymond A. Serway, Chris Vuille
Publisher:Cengage Learning
Text book image
University Physics (14th Edition)
Physics
ISBN:9780133969290
Author:Hugh D. Young, Roger A. Freedman
Publisher:PEARSON
Text book image
Introduction To Quantum Mechanics
Physics
ISBN:9781107189638
Author:Griffiths, David J., Schroeter, Darrell F.
Publisher:Cambridge University Press
Text book image
Physics for Scientists and Engineers
Physics
ISBN:9781337553278
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Text book image
Lecture- Tutorials for Introductory Astronomy
Physics
ISBN:9780321820464
Author:Edward E. Prather, Tim P. Slater, Jeff P. Adams, Gina Brissenden
Publisher:Addison-Wesley
Text book image
College Physics: A Strategic Approach (4th Editio...
Physics
ISBN:9780134609034
Author:Randall D. Knight (Professor Emeritus), Brian Jones, Stuart Field
Publisher:PEARSON
Kinetic Energy and Potential Energy; Author: Professor Dave explains;https://www.youtube.com/watch?v=g7u6pIfUVy4;License: Standard YouTube License, CC-BY