AP PhysicsMonday 14.04.01

Homework

Warm Up

Agenda1. Warm Up

Standards: 2b

Objective: SWBAT

Agenda1. Warm Up 2. Collect HW3. Finish Review

Warm Up

HomeworkStudy for Test

AP PhysicsTuesday 14.04.01

Standards: Electrostatics & Electric Circuits Work

Objective: SWBAT solve free response AP problems for tomorrows test.

10v

20Ω

10Ω5Ω1Ω

Find V,R,&I across each resistor. You don’t need Kirchoff’s Rules

AP PhysicsWednesday 14.04.02

Agenda1. Warm Up2. Collect HW3. Final Review Day

HomeworkStudy for Test

Warm UpHow much work must be done in order to move a proton from a 10 V potential to a 2 volt potential? How much work would it take if the charge was an electron?

Standards: Electrostatics & Electric Circuits Objective: SWBAT take your exam.

AP PhysicsThursday 14.04.03

HomeworkE#20

Warm Upa. What are the equations for the force, Electric Field, energy, and voltage due to 2 charges?b. What are the equations for the force, electric field, energy, and voltage due to two infinitely long parallel plates. Classify them in a table then compare your answers with your classmates

Standards: 2b Electricity Objective: SWBAT solve electricity FRQ’s

Agenda1. Warm Up2. FRQ’s E#20

AP PhysicsFriday 14.04.04

HomeworkE#21 Test MondayReview Answers on Twitter

Warm UpFind the capacitance of a capacitor with a plate separation of 4mm whose plates are 2m x 5m.

Agenda1. Warm Up 22nF2. Electric Circuits FRQ

Standards: Electric Circuits Objective: SWBAT solve ap frq’s

Kirchoff’s Rules

1. A point where three or more wires are joined is called a junction or node.

2. A path connecting two junctions is called a branch. A branch may contain one or more circuit elements and there may be more than two branches between two junctions.

3. ΣI=0 (Currents entering a junction are positive and currents exiting a junction are negative) Current in = Current out

4. ΣV=0 (Conservation of Energy)

Applying Kirchoff’s Rules p.601

1. Assign a current and direction of current for each branch in the circuit.

2. Identify the current loops and their directions. 3. Apply Kirchoff’s Rule for each loop to give you a unique set of

equations. ΣI=0 4. Apply the loop theorem ΣV=0 using V=IR

1985B3. An electron initially moves in a horizontal direction and has a kinetic energy of 2.0 x 103 electron–volts when it is in the position shown above. It passes through a uniform electric field between two oppositely charged horizontal plates (region I) and a field–free region (region II) before eventually striking a screen at a distance of 0.08 meter from the edge of the plates. The plates are 0.04 meter long and are separated from each other by a distance of 0.02 meter. The potential differenceacross the plates is 250 volts. Gravity is negligible.

E#19 Test Review FRQ

Kirchoff & RC Extra Credit

12V

Find the Ceq and the charge across each capacitor when fully charged. #2 only: Find the current (I) and the Req after the capacitors have fully charged.

3μF

3μF

20V

I

5μF

15μF4Ω8Ω3μF

3μF

2.

5Ω

10V5Ω 5Ω4.

5Ω5V

5Ω

5Ω

4V4Ω

2Ω 2V

3. 6Ω

1.

Use Kirchoff’s Law to find I1,I2 & I3.

Answers to be posted Sunday March 30th

E#20 Electrostatics FRQ Review

1975B2. Two identical electric charges +Q are located at two corners A and B of an isosceles triangle as shown right.a. How much work does the electric field do on a small test charge +q as the charge moves from point C to infinity,b. In terms of the given quantities, determine where a third charge +2Q should be placed so that the electric field at point C is zero. Indicate the location of this charge on the diagram right.

1989B2. Two point charges, Q1 and Q2, are located a distance 0.20 meter apart, as shown above. ChargeQ1 = +8.0μC. The net electric field is zero at point P, located 0.40 meter from Q1 and 0.20 meter from Q2a. Determine the magnitude and sign of charge Q2b. Determine the magnitude and direction of the net force on charge Q1c. Calculate the electrostatic potential energy of the system.d. Determine the coordinate of the point R on the x–axis between the two charges at which the electricpotential is zero.e. How much work is needed to bring an electron from infinity to point R. which was determined in theprevious part?

a. Q2=-2μC, b) 3.6 N to the right , c) -0.72 J, d) x=0.16m, e) 0

a) W=2kQq/a, b) +2C charge above point C at d=a√(2)

E#21 Electric Circuits Review

1990B3. A battery with an emf of 24 volts and an internal resistance of 1 ohm is connected to an external circuit as shown above. Determine each of the following:a. the equivalent resistance of the combination of the 4-ohm, 8-ohm, and 12-ohm resistors b. the current in the 5-ohm resistor c. the terminal voltage, VACd. the rate at which energy is dissipated in the 12-ohm resistor of the battery e. the magnitude of the potential difference V f. the power delivered by the battery to the external circuit

• 1985E2 (modified) In the circuit shown above, i1 and i2 are the currents through resistors Rl and R2, respectively. V1, V2, and Vc are the potential differences across resistor R1 resistor R2 and capacitor C, respectively. Initially the capacitor is uncharged.

• a. Calculate the current i1, immediately after switch S is closed. Assume switch S has been closed for a long time.

• b. Calculate the current i2

• c. Calculate the charge Q on the capacitor.• d. Calculate the energy U stored in the capacitor.

a. 6Ω, b. 2A, c. 22V, d) 12W, e)12V, f) 44W

a. I=0.006A, b) 0.002A, c)0.01C, d 10J