The wavelengths corresponding to the harmonics of a string with ...

[clmills979]

The wavelengths corresponding to the harmonics of a string with fixed ends can be found by saying that the length of the string must be equal to
 
  A)
 
  an odd number of quarter-wavelengths.
  B)
 
  an odd number of third-wavelengths.
  C)
 
  an odd number of half-wavelengths.
  D)
 
  an integer number of half-wavelengths.
  E)
 
  an integer number of wavelengths.

Question 2

A flywheel with a moment of inertia 6.00  106 kgm2 is spinning with an angular speed of 120 rev/s about a vertical axis while it sits at the north pole. The disk is turning counterclockwise when viewed from above.
 
  The disk is brought to a rest. Treat the earth as a uniform sphere with a mass 5.976  1024 kg and a radius 6.374  106 m. (a) What will be the magnitude of the change in angular momentum of the earth? (b) What will be the change in length of a day on Earth?

[ynlevi]

Answer to Question 1

D

Answer to Question 2

(a) 4.52  109 kgm2/s
(b) 5.53  10-20 s

[clmills979]

Gracias!

[robbielu01]

Great answer, keep it coming