A 3 kg mass is positioned at (0, 8), and a 1 kg mass is ...

[Pineappleeh]

A 3 kg mass is positioned at (0, 8), and a 1 kg mass is positioned at (12, 0). What are the coordinates of a 4 kg mass which will result in the center of mass of the system of three masses being located at the origin (0, 0)?
 
  A) (-3, -6)
  B) (-6, -3)
  C) (3, 6)
  D) (-12, -8)

Question 2

When a light wave enters into a medium of different optical density
 
  A) its speed and frequency change.
  B) its speed and wavelength change.
  C) its frequency and wavelength change.
  D) its speed, frequency, and wavelength change.

[flexer1n1]

Answer to Question 1

A

Answer to Question 2

B