PROBLEMS

A wave is given by What is the speed of the wave?
What is the amplitude?
What is the wave number k?
What is the wavelength?
What is the frequency f?
What is the direction of travel?
How could you alter the direction of travel?
What is the amplitude of the disturbance at x=3.0m, t=1.0s?
If this function reprsents the displacement of a string perpendicular to its length (as on a guitar string), at what transverse velocity does the string move at the position and time given above?
If this does not match the wave speed, why not?
Ocean waves strike a shoreline once every 5 seconds, and the wave speed is 2m/s.
What is the period of the waves?
What is the wavelength?
What is k?
What is ?
If a light wave's amplitude is tripled, what happens to the brightness or intensity of the light?
If a seismic wave is to double in energy, how much larger amplitude must it have?
How much momentum will a light wave that delivers per second to a surface deliver per second?
Given two waves of equal amplitude and wavelength, what relative phase is required to make the sum of the waves of equal amplitude to the two constituent waves?
Given two ocean waves - one of amplitude 1.0m and another 2.0m - of equal wavelength, what relative phase is required to make the resulting waves 1.5m in amplitude. What phase will the resulting wave have relative to the 1.0m wave?

ANSWERS

1. 0.6m/s 2. 2 (presumably meters, but mustn't be) 3. 5rad/m 4.

6. +x direction 7. change either sign of k or

8. -1.07 same issue with units as #2 9.

10. This is transverse motion of the string rather than the longitudinal wave on the string. 11. n/a 12. 5s 13. 10m 14.

15.

16. 9 times brighter 17.

times 18.

19.

20. tbd