In Copernicus's theory, retrograde planetary motion is explained ...

[Capo]

In Copernicus's theory, retrograde planetary motion is explained as
 
  A) a result of Earth's motion: as Earth passes another planet, that planet appears to move backward as seen against the background stars.
  B) due to the back-and-forth or oscillatory motion that planets make as they move along their circular orbits around Earth.
  C) due to the natural wandering of the celestial sphere of background stars.
  D) the backward part of the planet's loop-the-loop orbits around Earth.
  E) Actually he didn't have an explanation for this.

Question 2

An inductor has a current I(t) = (0.500
 
  A) cos(275 s-1)t flowing through it. If the maximum emf across the inductor is equal to 0.500 V, what is the self-inductance of the inductor?
  A) 4.37 mH
  B) 3.64 mH
  C) 2.75 mH
  D) 0.73 mH
  E) 1.43 mH

[Jayson]

Answer to Question 1

A

Answer to Question 2

B

[Capo]

TYSM

[atrochim]

Gracias!