10.4
What type of energy is stored when two charges are near each other?
Electric potential energy
What is the symbol for electric potential energy?
V
What does a capacitor store?
Electric charge and energy.
Energy can be converted between electric potential energy and what kind of energy?
Kinetic energy
What is the most expensive goblin card in clash royale?
3 musketeers
The formula for electric potential energy between two point charges is?
U = k(q1q2)/r
Electric potential energy is the amount of energy per what?
Charge
What is the equation for capacitance of a parallel-plate capacitor?
C = ε0A/d
When a positive charge moves in the direction of the electric field, what happens to its electric potential energy?
Decreases
What 2 numbers does our group love the most?
6 7!!!
If the distance between two charges doubles what happens to the electric potential energy?
One-half of its original value
Because potential energy is inversely proportional to the distance between charges.
A 1 C charge has 12 J of electric potential energy. What is the electric potential?
V = U/q
= 12/1
= 12V
A 5 µF capacitor is charged to 10 V. Find the charge stored.
Q = CV
= (5x10^-6 F)(10 V)
= 50 x 10^-6 C
or
= 50 µC
A +2 C charge moves from a point at 10 V to a point at 2 V. How much work is done by the electric field?
W = q∆V
= 2(10-2) = 16 J
What song do the lyrics "But I keep cruisin' can't stop, won't stop movin'" come from? And who is it by?
Shake it off by Taylor Swift
A charge of +2 µC is 0.5 m from a +3 µC charge. Find the electric potential energy.
U = k(q1q2)/r
(9x10^9)(2x10^-6)(3x10^-6)/0.5
= 0.108 J
A point charge of +3 µC is at a point where the electric potential is 9 V. Find the electric potential energy of the charge
U = qV
= (3 x 10^-6 C)(9 V)
= 27 x 10^-6 J
or
= 27 µJ
A parallel-plate capacitor has plate area 0.010 m^2 and separation 0.002 m. Calculate its capacitance.
C = ε0A/d
= (8.85 x 10^-12)(0.010)/0.002
= 4.43 x 10^-11 F
How is total energy conserved when a charge accelerates in an electric field?
Loss in potential energy = gain in kinetic energy
Which Christmas song was the first to be broadcast from space?
Jingle Bells
Two identical charges repel each other with a force of 4 N when 0.5 m apart. What is the electric potential energy.
The charges are identical, so q1 = q2 = q
By comparing the formula we see that U is equal to F multiplied by the distance.
U = F x r
= 4 N x 0.5 m
= 2 J
How does electric potential vary with distance from a point charge?
V = kQ/r
So it decreases as distance increases because electric potential due to a point charge varies inversely with the distance from the charge.
A parallel plate capacitor has plate area 0.020 m^2. The capacitor is charged so that it holds 5.0 x 10^-9 C. The electric field between the plates with no dielectric is 2.82 x 10^4 N/C. A dielectric with constant k = 5 is inserted between the plates. Find the electric field after the dielectric is inserted.
E = Q/Kε0A
= (2.82 x 10^4)/5
= 5.64 x 10^3 N/C
A +4.0 µC charge moves 0.020 m upward in a uniform electric field of 800 N/C that points upward. How much does the electric field do on the charge?
W = qEd
= (4.0 x 10^-6)(800)(0.020)
= 0.064 J
What is Mrs. Wedermyer's favorite drink (school appropriate answers only!)?
Celsius peach vibes!