College Physics (7th Edition)

Published by Pearson
ISBN 10: 0-32160-183-1
ISBN 13: 978-0-32160-183-4

Chapter 5 - Work and Energy - Learning Path Questions and Exercises - Exercises - Page 175: 14

Answer

a). $147.5kJ$ b). $-122.5kJ$ c). $25kJ$

Work Step by Step

a). $h=\frac{1}{2}at^{2}=25m$ $F=m(g+a)=500(9.8+2)=5900N$ $W=5900\times25=147.5kJ$ b). $W=mgh=500\times(-9.8)\times25=-122.5kJ$ c). Net work done on helicopter $W=147.5-122.5=25kJ$
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.

GradeSaver will pay $15 for your literature essays
GradeSaver will pay $25 for your college application essays
GradeSaver will pay $50 for your graduate school essays – Law, Business, or Medical
GradeSaver will pay $10 for your Community Note contributions
GradeSaver will pay $500 for your Textbook Answer contributions