Giancoli's Physics: Principles with Applications, 7th Edition

6

Work and Energy

Change chapter6-1: Work, Constant Force

6-2: Work, Varying Force

6-3: Kinetic Energy; Work-Energy Principle

6-4 and 6-5: Potential Energy

6-6 and 6-7: Conservation of Mechanical Energy

6-8 and 6-9: Law of Conservation of Energy

6-10: Power

Question by Giancoli, Douglas C., Physics: Principles with Applications, 7th Ed., ©2014, Reprinted by permission of Pearson Education Inc., New York.

Problem 46

Q

A

$3.7\times10^7\textrm{ J}$

In order to watch this solution you need to have a subscription.

VIDEO TRANSCRIPT

This is Giancoli Answers with Mr. Dychko. All of the kinetic energy that the two trains have is going to get converted into thermal energy because they come to a stop and none of that kinetic energy has turned into potential energy, we assume, and so it all becomes thermal. So we take the kinetic energy of one of the trains and since there are two of them, we multiply by 2. So we have one-half times the mass of a single train times its velocity squared times for two trains and that gives us *m v squared* is our formula for thermal energy. The 66,000 kilograms times 85 kilometers per hour converted into meters per second by dividing by 3.6 and we square that speed and that gets 3.7 times 10 to the 7 joules of thermal energy after the crash.

Giancoli Answers, including solutions and videos, is copyright © 2009-2023 Shaun Dychko, Vancouver, BC, Canada. Giancoli Answers is not affiliated with the textbook publisher. Book covers, titles, and author names appear for reference purposes only and are the property of their respective owners. Giancoli Answers is your best source for the 7th and 6th edition Giancoli physics solutions.