What is the strength of the electric field between two plate
What is the strength of the electric field between two plates separated by a distance 6.0 cm and with a potential difference of 2.30×104 V.
Correct, computer gets: 3.83E+05 V/m
In the previous problem, if a charge of 0.10 C is released from rest at the positive plate, how much kinetic energy will it have when it reaches the negative plate?
HINT: The increase in kinetic energy must be equal to the decrease in potential energy
THE ANSWER IS NOT .0023 J or -.0023 J
Solution
Potential difference V = 2.3 x10 4 volt
Distance between two plates d = 6 cm = 0.06 m
The strength of the electric field between two plates E = V/d
=(2.3x10 4) / 0.06
= 3.83 x10 5 volt/m
Charge q = 0.1 x10 -6 C
increase in kinetic energy = Potential energy decrease
(1/2) m[v 2 -u 2] = Vq Where u = initial velocity = 0
=[2.3x10 4x0.1x10 -6 ]
= 2.3x10 -3 J
= 2.3 mJ
