A 320-g ball and a 400-g ball are attached to the two ends of a ...

[jparksx]

A 320-g ball and a 400-g ball are attached to the two ends of a string that goes over a pulley with a radius of 8.7 cm. Because of friction in its axle, the pulley does not begin to rotate.
 
  What is the magnitude of the frictional torque at the axle of the pulley if the system remains at rest when the balls are released? A) 0.068 N  m
  B) 0.61 N  m
  C) 0.079 N  m
  D) 0.063 N  m
  E) 0.00070 N  m

Question 2

A certain ideal gas has a molar specific heat at constant volume 7R/2. What is its molar specific heat at constant pressure?
 
  A) 5R/2
  B) 3R/2
  C) 8R
  D) 9R/2
  E) 6R

[phuda]

Answer to Question 1

A

Answer to Question 2

D