776_Physics ProblemsTechnical Physics

# 776_Physics ProblemsTechnical Physics - 116*P27.40 Current...

This preview shows page 1. Sign up to view the full content.

116 Current and Resistance *P27.40 The battery takes in energy by electric transmission P t V I t = = × F H G I K J = a f a f e j 2 3 13 5 10 4 2 3 600 469 3 . . . J C C s h s 1 h J. It puts out energy by electric transmission V I t a f a f e j = × F H G I K J = 1 6 18 10 2 4 3 600 249 3 . . J C C s h s 1 h J. (a) efficiency = = = useful output total input J 469 J 249 0 530 . (b) The only place for the missing energy to go is into internal energy: 469 249 221 J J J int int = + = E E (c) We imagine toasting the battery over a fire with 221 J of heat input: Q mc T T Q mc = = = ° = ° 221 15 1 J kg C 0.015 kg 975 J C . P27.41 P P 0 2 0 2 0 2 2 140 120 1 361 = = F H G I K J = F H G I K J = V R V R V V a f b g . % . . =
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern