Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)

Published by Pearson
ISBN 10: 0133942651
ISBN 13: 978-0-13394-265-1

Chapter 15 - Oscillations - Conceptual Questions - Page 414: 9


(a) The spring's equilibrium length is 20 cm. (b) $x = 14 ~cm$ $x = 26 ~cm$ (c) The maximum kinetic energy is 7 joules. (d) $x = 11.5 ~cm$ $x = 28.5 ~cm$

Work Step by Step

(a) At x = 20 cm, $U_s = 0$. Therefore, the spring is neither stretched nor compressed when x = 20 cm. Therefore, the spring's equilibrium length is 20 cm. (b) The turning points occur when $U_s = TE$. This happens when x = 14 cm and x = 26 cm. (c) The maximum kinetic energy is equal to the total energy in the system which is 7 joules. (d) We can find the spring constant as: $\frac{1}{2}k(0.06~m)^2 = 7~J$ $k = \frac{(2)(7~J)}{(0.06~m)^2}$ $k = 3900~N/m$ If the total energy is doubled, then the total energy is 14 joules. We can find $d$ when $U_s = TE$; $U_s = TE$ $\frac{1}{2}kd^2 = TE$ $d = \pm ~\sqrt{\frac{2~TE}{k}}$ $d = \pm ~\sqrt{\frac{(2)(14~J)}{3900~N/m}}$ $d = 0.085~m = 8.5~cm$ The turning points are x = 11.5 cm and x = 28.5 cm.
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.