A coin is 12 cm in front of a convex lens with focal length of ...

[Awilson837]

A coin is 12 cm in front of a convex lens with focal length of magnitude 4.0 cm. Where is the image?
 
  A) 8.0 cm behind the lens
  B) 6.0 cm in front of the lens
  C) 6.0 cm behind the lens
  D) 4.0 cm in front of the lens

Question 2

A small gas laser of the type used in classrooms may radiate light at a power level of 2.0 mW.
 
  If the wavelength of the laser light is 642 nm, how many photons does it emit per second? (c = 3.0  108 m/s, h = 6.626  10-34 J  s)

[jgranad15]

Answer to Question 1

C

Answer to Question 2

6.5  1015

[Awilson837]

YES! Correct, THANKS for helping me on my review

[marict]

Thanks for the timely response, appreciate it