A charge Q1 is located at coordinates (x = +a, y = +a). A second ...

[shenderson6]

A charge Q1 is located at coordinates (x = +a, y = +a). A second charge Q2 , identical to Q1, is located in such a way that the net electric field at the origin of the coordinate axis (x = 0, y = 0 ) is equal to 0.
 
  What are the coordinates of Q2?
  A)
 
  x= -a, y = +a
  B)
 
  x = +a, y = +a
  C)
 
  x = 0, y = 0
  D)
 
  x = -a, y = -a
  E)
 
  x = +a, y = -a

Question 2

You are driving along a highway at 35.0 m/s when you hear the siren of a police car approaching you from behind and you perceive the frequency as 1470 Hz.
 
  You are relieved that he is in pursuit of a different speeder when he continues past you, but now you perceive the frequency as 1400 Hz. What is the frequency of the siren in the police car? The speed of sound in air is 343 m/s.
  A)
 
  1300 Hz
 
  B)
 
  1320 Hz
 
  C)
 
  1430 Hz
 
  D)
 
  1360 Hz
 
  E)
 
  1370 Hz

[pangili4]

Answer to Question 1

D

Answer to Question 2

C