(a) What is the average useful power output (in W) of a person who does 6.80 x 106 J of useful work in 8.40 h? W (b) Working at this rate, how long (in s) will it take this person to lift 1700 kg of bricks 1.40 m to a platform? (Work done to lift his body can be omitted because it is not considered useful output here.)

College Physics
11th Edition
ISBN:9781305952300
Author:Raymond A. Serway, Chris Vuille
Publisher:Raymond A. Serway, Chris Vuille
Chapter1: Units, Trigonometry. And Vectors
Section: Chapter Questions
Problem 1CQ: Estimate the order of magnitude of the length, in meters, of each of the following; (a) a mouse, (b)...
icon
Related questions
Topic Video
Question
### Educational Task: Calculating Power Output and Time for Lifting

#### (a) Calculation of Average Useful Power Output

**Problem Statement:**  
What is the average useful power output (in watts, W) of a person who performs \(6.80 \times 10^6\) joules (J) of useful work in 8.40 hours?

**Solution:**  
To find the average power output, use the formula:
\[ \text{Power} = \frac{\text{Work}}{\text{Time}} \]

- Work = \(6.80 \times 10^6\) J
- Time = 8.40 hours 

*Note:* Convert the time from hours to seconds (since power in watts is joules per second).
\[ 8.40 \, \text{hours} = 8.40 \times 3600 \, \text{seconds} \]

Fill in the answer box with the calculated power in watts (W).

#### (b) Calculation of Time Required for Lifting

**Problem Statement:**  
Working at this rate, how long (in seconds, s) will it take this person to lift 1700 kg of bricks 1.40 meters to a platform? (Work done to lift their body can be omitted because it is not considered useful output here.)

**Solution:**  
To find the time required, use the formula:
\[ \text{Time} = \frac{\text{Work}}{\text{Power}} \]

First, calculate the work required to lift the bricks:
\[ \text{Work} = \text{mass} \times \text{gravity} \times \text{height} \]
- Mass = 1700 kg
- Gravity = 9.8 m/s\(^2\)
- Height = 1.40 m

\[ \text{Work} = 1700 \times 9.8 \times 1.40 \, \text{J} \]

Use the previously calculated power from part (a) to find the time.

Fill in the answer box with the calculated time in seconds (s).

### Note:
These calculations help understand the relationship between work, power, and time in physical processes. Ensure all units are consistent while calculating.
Transcribed Image Text:### Educational Task: Calculating Power Output and Time for Lifting #### (a) Calculation of Average Useful Power Output **Problem Statement:** What is the average useful power output (in watts, W) of a person who performs \(6.80 \times 10^6\) joules (J) of useful work in 8.40 hours? **Solution:** To find the average power output, use the formula: \[ \text{Power} = \frac{\text{Work}}{\text{Time}} \] - Work = \(6.80 \times 10^6\) J - Time = 8.40 hours *Note:* Convert the time from hours to seconds (since power in watts is joules per second). \[ 8.40 \, \text{hours} = 8.40 \times 3600 \, \text{seconds} \] Fill in the answer box with the calculated power in watts (W). #### (b) Calculation of Time Required for Lifting **Problem Statement:** Working at this rate, how long (in seconds, s) will it take this person to lift 1700 kg of bricks 1.40 meters to a platform? (Work done to lift their body can be omitted because it is not considered useful output here.) **Solution:** To find the time required, use the formula: \[ \text{Time} = \frac{\text{Work}}{\text{Power}} \] First, calculate the work required to lift the bricks: \[ \text{Work} = \text{mass} \times \text{gravity} \times \text{height} \] - Mass = 1700 kg - Gravity = 9.8 m/s\(^2\) - Height = 1.40 m \[ \text{Work} = 1700 \times 9.8 \times 1.40 \, \text{J} \] Use the previously calculated power from part (a) to find the time. Fill in the answer box with the calculated time in seconds (s). ### Note: These calculations help understand the relationship between work, power, and time in physical processes. Ensure all units are consistent while calculating.
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 2 steps

Blurred answer
Knowledge Booster
Mechanical Work done
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.
Similar questions
Recommended textbooks for you
College Physics
College Physics
Physics
ISBN:
9781305952300
Author:
Raymond A. Serway, Chris Vuille
Publisher:
Cengage Learning
University Physics (14th Edition)
University Physics (14th Edition)
Physics
ISBN:
9780133969290
Author:
Hugh D. Young, Roger A. Freedman
Publisher:
PEARSON
Introduction To Quantum Mechanics
Introduction To Quantum Mechanics
Physics
ISBN:
9781107189638
Author:
Griffiths, David J., Schroeter, Darrell F.
Publisher:
Cambridge University Press
Physics for Scientists and Engineers
Physics for Scientists and Engineers
Physics
ISBN:
9781337553278
Author:
Raymond A. Serway, John W. Jewett
Publisher:
Cengage Learning
Lecture- Tutorials for Introductory Astronomy
Lecture- Tutorials for Introductory Astronomy
Physics
ISBN:
9780321820464
Author:
Edward E. Prather, Tim P. Slater, Jeff P. Adams, Gina Brissenden
Publisher:
Addison-Wesley
College Physics: A Strategic Approach (4th Editio…
College Physics: A Strategic Approach (4th Editio…
Physics
ISBN:
9780134609034
Author:
Randall D. Knight (Professor Emeritus), Brian Jones, Stuart Field
Publisher:
PEARSON