What is the magnitude of a the vertical electric field that will ...

[cnetterville]

What is the magnitude of a the vertical electric field that will balance the weight of a plastic sphere of mass that has been charged to -3.0 nC? (k = 1/40 = 9.0  109 N  m2/C2)
 
  A) 6.9  106 N/C
  B) 7.8  105 N/C
  C) 1.5  106 N/C
  D) 2.1  106 N/C

Question 2

A person uses corrective glasses of power -8.5 D that are worn 2.0 cm from her eye.
 
  (a) Is she nearsighted or farsighted?
  (b) What is her far point without glasses?

[trog]

Answer to Question 1

A

Answer to Question 2

(a) nearsighted (b) 14 cm

[cnetterville]

Both answers were spot on, thank you once again

[trog]

Great! Please up vote