A +7.00 C point charge and -9.00 C point charge are placed along ...

[Wadzanai]

A +7.00 C point charge and -9.00 C point charge are placed along the x-axis at x = 0.000 cm and x = 40.0 cm, respectively.
 
  Where must a third charge, q, be placed along the x-axis so that it does not experience any net electric force due to the other two charges?
  A) -0.200 m
  B) 2.99 m
  C) -0.187 m
  D) -2.99 m
  E) 0.187 m

Question 2

An ideal massless spring with a spring constant of 2.00 N/m is attached to an object of 75.0 g. The system has a small amount of damping.
 
  If the amplitude of the oscillations decreases from 10.0 mm to 5.00 mm in 15.0 s, what is the magnitude of the damping constant b?
  A) 0.0100 kg/s
  B) 0.00693 kg/s
  C) 0.00762 kg/s
  D) 0.00857 kg/s
  E) 0.0462 kg/s

[anyusername12131]

Answer to Question 1

D

Answer to Question 2

B