# Transverse displacement, tricky MC

1. Jun 15, 2008

### K3nt70

1. The problem statement, all variables and given/known data

The transverse displacement of a streched string from equilibrium as a function of time and position is given by:
y=0.13cos(3x+27t). x and y are in m; t is in s.
(Select T-True, F-False, G-Greater than, L-Less than, E-Equal to, If the first is T and the rest F, enter
TFFF).

A) The speed of the wave is ..... 8 m/s
B) The wavelength is ..... 1 m
C) The wave moves in the positive x direction
D) The period is ..... 0.1 s

2. Relevant equations

The only one i was able to solve for was D, using

$$\omega$$ = $$\frac{2\pi}{T}$$

3. The attempt at a solution

Solving for T: T= 2pi/27 gives T= 0.23 s. This designates D as G (greater than).
I cant really figure out how we get the others from T... My main problem is Finding velocity. If i find velocity, i can find the rest. My secondary problem is finding out the direction of the wave.

p.s. even my tutor couldn't get this one.

Last edited: Jun 15, 2008
2. Jun 15, 2008

### Staff: Mentor

Last edited by a moderator: Apr 23, 2017
3. Jun 15, 2008

### K3nt70

Got it worked out, thanks. My problem was not recognizing what k was in this situation (angular wave number).