Work and Power in Cycling
When you ride a bicycle at constant speed, almost all of the energy you expend goes into the work you do against the drag force of the air. In this problem, assume that all of the energy expended goes into working against drag. As we saw in Section 5.7, the drag force on an object is approximately proportional to the square of its speed with respect to the air. For this problem, assume that F α v2 exactly and that the air is motionless with respect to the ground unless noted otherwise. Suppose a cyclist and her bicycle have a combined mass of 60 kg and she is cycling along at a speed of 5 m/s.
88. If she doubles her speed to 10 m/s, how much energy does she use in cycling 1 km?
A. 20 kJ
B. 40 kJ
C. 200 kJ
D. 400 kJ
Want to see the full answer?
Check out a sample textbook solutionChapter 10 Solutions
Modified Mastering Physics with Pearson eText -- Standalone Access Card -- for College Physics: A Strategic Approach (4th Edition)
Additional Science Textbook Solutions
Microbiology with Diseases by Body System (5th Edition)
Campbell Essential Biology (7th Edition)
Biology: Life on Earth (11th Edition)
Physics for Scientists and Engineers: A Strategic Approach, Vol. 1 (Chs 1-21) (4th Edition)
Laboratory Experiments in Microbiology (12th Edition) (What's New in Microbiology)
Campbell Biology (11th Edition)
- Find the ratio of the diameter of silver to iron wire, if they have the same resistance per unit length (as they might in household wiring). d Ag = 2.51 dFe ×arrow_forwardShow that the units 1 v2/Q = 1 W, as implied by the equation P = V²/R. Starting with the equation P = V²/R, we can get an expression for a watt in terms of voltage and resistance. The units for voltage, V, are equivalent to [? v2 v2 A, are equivalent to J/C ✓ X . Therefore, 1 = 1 = 1 A V1 J/s Ω V-A X = 1 W. . The units for resistance, Q, are equivalent to ? The units for current,arrow_forwardPlease solve and answer the question correctly please. Thank you!!arrow_forward
- What is the equivalent resistance between points A and B of the network shown in the figure? A • 12 B 4.0 6.0 Ω 8.0 Ωarrow_forwardAccording to the provided information answer the question accorrding to grade 11 physics Jerry has decided to give up his part-time job for a new career, cat-burglar! Jerry loves the idea of dressing up like a cat all day and of course the chance of meeting Cat Woman! On Jerry's first "job" he figures out his escape plan. He travels 3.0 km south for 15 minutes and then 8.0 km west for 1.5 hours before reaching his house. Draw a sketch diagram of the path he took with all the appropriate labels.arrow_forwardPlease solve and answer all parts of the question correctly please. Thank you!!arrow_forward
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781285737027Author:Raymond A. Serway, Chris VuillePublisher:Cengage Learning
- University Physics Volume 1PhysicsISBN:9781938168277Author:William Moebs, Samuel J. Ling, Jeff SannyPublisher:OpenStax - Rice UniversityCollege PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781938168000Author:Paul Peter Urone, Roger HinrichsPublisher:OpenStax College