DAY 89

Questions? Ask Mr. Potkin, or message me via Remind App

Goals: SWBAT...

1. To solve momentum conservation problems

Warm-Up 89 (5min):

Consider pool (billiard) balls. The 8-ball and cue ball each have a mass of 0.25 kg. The cue ball is moving at 2 m/s towards the 8-ball, which is at rest. The cue ball (mass 1) stops during the collision with the 8-ball (mass 2), which moves away with some unknown final velocity. 

a. List the given information

b. What is conserved?

c. What is the velocity of mass 2? Back up your answer by solving the appropriate equation

CLASSWORK

1. #089A: Conservation of Momentum Practice Problems

Solve all problems (skip 5a, it was your warm-up) in your notebook. 

LINK: https://drive.google.com/file/d/0B-AiPYEb3nFVZVJQekNiUjRGcG8/view

2. Complete any incomplete assignments from this week

3. Notebook Check next Friday

Learning at Home/HW

- Complete the CW from today 

- I may add a video later today. Check back. I'll send a message via Remind App

GOALS: 

1. SWBAT understand the basic properties of electric charge.

2. compare electric force with gravitational force.

3. explain why a charged object in an electric field is considered to have electrical potential energy. 

4. Express the units for electric potential.

5. Distinguish between potential and potential difference.

6. Solve problems using potential in uniform electric fields.

WARM-UP

• 1. Moving an electron within an electric field would change the ____ the electron.

     1. a. mass of

1. b. amount of charge onc. potential energy of

2. Do you think you could move a proton in an electric field? Why/why not?

CLASSWORK

1. HW Review

2. Video:

https://www.youtube.com/watch?v=TBt-kxYfync&index=2&list=WL&t=0s

3. Electric Potential Difference part 2

- take notes, answer practice questions

- Slideshow pages : LINK

4. Practice Problems

2. If an electrical circuit were analogous to a water circuit at a water park, then the battery voltage would be comparable to _____.

a. the rate at which water flows through the circuit

b. the speed at which water flows through the circuit

c. the distance that water flows through the circuit

d. the water pressure between the top and bottom of the circuit

e. the hindrance caused by obstacles in the path of the moving water

3. If the electrical circuit in your iPhone thing were analogous to a water circuit at a water park, then the battery would be comparable to _____.

a. the people that slide from the elevated positions to the ground

b. the obstacles that stand in the path of the moving water

c. the pump that moves water from the ground to the elevated positions

d. the pipes through which water flows

e. the distance that water flows through the circuit

4. Which of the following is true about the electrical circuit in your flashlight?

a. Charge moves around the circuit very fast - nearly as fast as the speed of light.

b. The battery supplies the charge (electrons) that moves through the wires.

c. The battery supplies the charge (protons) that moves through the wires.

d. The charge becomes used up as it passes through the light bulb.

e. The battery supplies energy that raises charge from low to high voltage.

f. ... nonsense! None of these are true.

5. If a battery provides a high voltage, it can ____.

a. do a lot of work over the course of its lifetime

b. do a lot of work on each charge it encounters

c. push a lot of charge through a circuit

d. last a long time

The diagram below at the right shows a light bulb connected by wires to the + and - terminals of a car battery. Use the diagram in answering the next four questions.

6. Compared to point D, point A is _____ electric potential.

a. 12 V higher in

b. 12 V lower in

c. exactly the same

d. ... impossible to tell

7. The electric potential energy of a charge is zero at point _____.

8. Energy is required to force a positive test charge to move ___.

a. through the wire from point A to point B

b. through the light bulb from point B to point C

c. through the wire from point C to point D

d. through the battery from point D to point A

9. The energy required to move +2 C of charge between points D and A is ____ J.