A person in a rocket ship traveling past the earth at a speed of 0.500c fires a laser gun in the ...

A person in a rocket ship traveling past the earth at a speed of 0.500c fires a laser gun in the forward direction. With what speed does an observer on Earth see the light pulse travel?
 
  What will be an ideal response?

Question 2

What is the surface temperature of a star, given that its radiation peak occurs at a frequency of 1.86  1015 Hz?
 
  A) 17,000 K
  B) 14,500 K
  C) 19,000 K
  D) 20,400 K
  E) 18,000 K

Question 3

The wavelength of an electromagnetic wave is 600 nm. What is its frequency?
 
  A) 200  1012 Hz
  B) 300  1012 Hz
  C) 400  1012 Hz
  D) 500  1012 Hz
  E) 600  1012 Hz

Question 4

A mirror with a focal length -25 cm has a 4.0 cm tall object placed 100 cm in front of it. What is the position of the image?
 
  A) 20 cm behind the mirror
  B) 25 cm behind the mirror
  C) 100 cm in front of the mirror
  D) 25 cm in front of the mirror
  E) 20 cm in front of the mirror