HW9 Solution

# HW9 Solution - lew (dl9564) hk9 Opyrchal (41104) 1 This...

This preview shows pages 1–2. Sign up to view the full content.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: lew (dl9564) hk9 Opyrchal (41104) 1 This print-out should have 9 questions. Multiple-choice questions may continue on the next column or page find all choices before answering. 001 10.0 points A body oscillates with simple harmonic mo- tion along the x-axis. Its displacement varies with time according to the equation A = A sin parenleftBig t + 3 parenrightBig , where = radians per second, t is in sec- onds, and A = 6 m. What is the phase of the motion at t = 8 . 8 s? Correct answer: 28 . 6932 rad. Explanation: Let : t = 8 . 8 s and = . x = A sin( t + ) The phase is the angle in the argument of the sine function, and from the problem state- ment we see it is = t + 3 = ( rad / s) (8 . 8 s) + 3 = 28 . 6932 rad . 002 (part 1 of 4) 10.0 points A 15 . 3 kg mass is suspended on a 1 10 5 N / m spring. The mass oscillates up and down from the equilibrium position y eq = 0 according to y ( t ) = A sin( t + ) . Find the angular frequency of the oscillat- ing mass. Correct answer: 80 . 8452 s 1 . Explanation: Let : M = 15 . 3 kg and k = 1 10 5 N / m . When the mass moves out of equilibrium, it suffers a net restoring force F net y = F spring Mg = k ( y y eq ) = ky , and accelerates back towards the equilibrium position at the rate a y = F net y M = k M y . Therefore, the mass oscillates harmonically with angular frequency = radicalbigg a y y = radicalbigg k M = radicalBigg 1 10 5 N / m 15 . 3 kg = 80 . 8452 s 1 ....
View Full Document

## This note was uploaded on 01/22/2009 for the course PHYS Phys 106 taught by Professor Opyrachal during the Fall '08 term at NJIT.

### Page1 / 4

HW9 Solution - lew (dl9564) hk9 Opyrchal (41104) 1 This...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online