Fig. 10-3 illustrates a simplified roller bearing. The outer ...

[urbanoutfitters]

Fig. 10-3 illustrates a simplified roller bearing. The outer hollow cylinder has a radius of 1.20 cm and is stationary. The inner cylinder has a radius of 1.00 cm and is rotating at 9.00 rpm.
 
  Between the two cylinders are several small cylinders with a radius of 0.100 cm, which roll without slipping on both the inner and outer cylinders. Only one of these cylinders is shown in the figure. How long does it take a small cylinder to complete a full revolution around the inner cylinder? A)
 
  6.00 s
 
  B)
 
  14.7 s
 
  C)
 
  5.64 s
 
  D)
 
  0.542 s
 
  E)
 
  1.38 s

Question 2

The closest known star to our solar system is Alpha Centauri, which is approximately 4.30 light years away. A spaceship with a constant speed of 0.800c relative to the earth travels from Earth to this star.
 
  (a) How much time would elapse during the trip on a clock on board the spaceship?
  (b) How much time would elapse during the trip on a clock on Earth?

[bitingbit]

Answer to Question 1

B

Answer to Question 2

(a) 3.23 y (b) 5.38 y

[urbanoutfitters]

Thank you!

[bitingbit]

Always glad to help...