At the first minima on either side of the central bright spot in ...

[j.rubin]

At the first minima on either side of the central bright spot in a double-slit experiment, light from each opening arrives
 
  A)
 
  in phase.
  B)
 
  45 out of phase.
  C)
 
  90 out of phase.
  D)
 
  180 out of phase.
  E)
 
  none of the given answers

Question 2

An object of weight W is in free-fall close to the surface of Earth. What is the force that the object exerts on Earth?
 
  A)
 
  a force greater than W
  B)
 
  a force less than W
  C)
 
  a force equal to W
  D)
 
  no force at all
  E)
 
  cannot be determined without additional information

[kescobar@64]

Answer to Question 1

D

Answer to Question 2

C

[j.rubin]

Excellent

[dantucker]

Gracias!