The speed of waves on a thin wire is 150 m/s. The density of the ...

[daltonest1984]

The speed of waves on a thin wire is 150 m/s. The density of the material that the wire is made of is 5000 kg/m3. The wire has a 0.500 mm diameter circular crosssection. What is the tension that the wire is under?
 
  A)
 
  76.2 N
 
  B)
 
  22.1 N
 
  C)
 
  88.4 N
 
  D)
 
  0.147 N
 
  E)
 
  56.7 N

Question 2

A solenoid of inductance L = 50 mH has a magnetic energy U = 3 x 10-4 J with a density u = 0.0042 J/ m3. What is the winding density n of the solenoid?
 
  A)
 
  58 turns/m
  B)
 
  1584 turns/m
  C)
 
  1200 turns/m
  D)
 
  234 turns/m
  E)
 
  746 turns/m

[yuyiding]

Answer to Question 1

B

Answer to Question 2

E