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Tuesday, November 15, 2011

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Bellringer

- If you have paperwork to turn in, please leave it on your desk. I will get it.
- Copy the “I can” statement from the board.
- Fill out your agenda.
- Remember CHAMPs expectations!

CHAMPs

C: 0 (when the bell rings)

H: quietly ask a neighbor; after bell, raise hand

A: independent work

M: 0 (after bell rings)

P: silently completing bellringer

Balanced and Unbalanced Forces

Introduction to Unit 3 – Forces and Motion

Passing Lane

Notes

- Key Idea
- Detail
- Detail

- Key Idea
- Detail
- Detail

- A force is a push or pull that causes an object to move, stop, or change direction

A. A push

B. A pull

C. Anything that causes a change in motion

D. All of the above

- Units are Newtons (N) 1N=1kg m/s2 (mass x acceleration)

- Forces come in pairs
- Forces have a magnitude and a direction

Magnitude: 5N

Direction: north (up)

5N, north (up)

- Forces can be represented by arrows.
- The size of the arrow represents the magnitude and the point shows its direction.

- True
- False

- A. Grams
- B. Meters per second
- C. Newtons
- D. Arrows

- A star
- An arrow
- A dotted line
- The letter “F”

- When all forces are combined together it is called the net force.
- Forces in the same direction combine by addition.
- Forces in opposite directions combine by subtraction.

Addition of Forces

Bellringer

- If you have paperwork to turn in, please leave it on your desk. I will get it.
- Copy the “I can” statement from the board.
- Fill out your agenda.
- Remember CHAMPs expectations!

CHAMPs

C: 0 (when the bell rings)

H: quietly ask a neighbor; after bell, raise hand

A: independent work

M: 0 (after bell rings)

P: silently completing bellringer

- Forces occur in pairs and they can be either balanced or unbalanced

- Balanced forces do not cause change in motion
- Net Forces=0
- They are equal in size and opposite in direction

- Draw a Balanced Seesaw Showing Forces

- An unbalanced force always causes a change in motion.
- When unbalanced forces act in opposite directions you can find the net force
- Net force
- Magnitude
- The difference between the two forces

- Direction
- Direction of the largest force

- Magnitude

- Net force

3 N, right 6 N, left = 3N, left

4 N, left 10 N, right =

6N, right

5 N, right + 10 N, right =

15N, right

Draw An Unbalanced Seesaw Showing Forces

Two tugboats are moving a barge. Tugboat A exerts a force of 3000 newtons on the barge. Tugboat B exerts a force of 5000 newtons in the same direction. What is the combined force on the barge?

A. 2000 Newtons

B. 5000 Newtons

C. 3000 Newtons

D. 8000 Newtons

Draw arrows showing the individual and combined forces of the tugboats.

Suppose that Tugboat A exerts a force of 2000 newtons on the barge and Tugboat B exerts a force of 4000 newtons in the opposite direction. What is the combined force on the barge?

A. 2000 Newtons

B. 4000 Newtons

C. 6000 Newtons

D. 8000 Newtons

- Draw arrows showing the individual and combined forces of the tugboats

A. Yes

B. No

- Forces are a PUSH or PULL
- Unbalanced Forces cause a change in motion.
- No motion occurs when forces are balanced.
- Forces are measure in NEWTONS.
- Forces are represented by arrows.
- The overall force is called the NET FORCE

Passing Lane

Write 3 questions that can be answered using today’snotes.

(*Place the questions next to the key ideas.)

Notes

- Key Idea
- Detail
- Detail

- Key Idea
- Detail
- Detail

- Gauge your understanding of today’s “I can” statement. (Check the line.)
- On the lines underneath, prove the “I can” statement. (In other words, explain the difference between balanced and unbalanced forces.)