You have discovered a star system consisting of three equally ...

[crobinson2013]

You have discovered a star system consisting of three equally spaced stars of equal mass arranged in a straight line. The two outermost stars, Zenith and Nadir, revolve synchronously around the central star, Janus.
 
  What is the period of revolution for this system in terms of M, the mass of each of the stars, and R, the radius of the circular orbit of Zenith and Nadir? A) 2R3/2/(GM)1/2  (3/2)1/2
  B) 2R3/2/(GM)1/2  (2/3)1/2
  C) 2R3/2/(GM)1/2  (4/5)1/2
  D) 2R3/2/(GM)1/2  (5/4)1/2
  E) 2R3/2/(GM)1/2  (7/5)1/2

Question 2

A solenoid of 200 turns carrying a current of 2 A has a length of 25 cm. What is the magnitude of the magnetic field at the center of the solenoid?
 
  A) 2 mT
  B) 3 mT
  C) 4 mT
  D) 5 mT
  E) 6 mT

[s.meritte]

Answer to Question 1

C

Answer to Question 2

A

[crobinson2013]

Wow, this really help

[Chelseyj.hasty]

Thanks for the timely response, appreciate it