## Thursday, December 12, 2013

### Unit 4 Physics II Day 19: Unit 4 Physics II Exam Review

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Unit 4: Physics II Exam Review
Learning Goal 1 – Important Forces (6.8A)

1) Circle which definition for force is best?

“A push or a pull.”
“Something that causes motion.”
“Force is the same thing as motion.”

2) Friction is a force that resists motion between two objects.

3) Gravity is a force that comes from the center of the Earth and it is a (push    /   pull).

4) True/False:
T. Objects of the same shape, but different mass, fall at the same rate.
F. Friction can cause objects to speed up.
F. Gravity comes from the atmosphere.
T. The sun has more gravity than the earth.

Learning Goal 2: Balanced and Unbalanced Forces (6.8B)
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5) Write “balanced” or “unbalanced by each of the diagrams.
unbalanced.
balanced.
6) A rocket pushes up with a force of 5, 5567 newtons while gravity pulls down with a force of 3,100 newtons. Draw a diagram and find the net force on the rocket.
Diagram:                                                                                Solve: 2467 N

7) What is the net force in the diagram to the left?
50 N

8) In the diagram to the left, which way will motion occur? Left

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10) Circle does the diagram below represent a        balanced          or            unbalanced force?

11) Which way will the piano move? Left

Learning Goal 3: Speed (6.8C)

11) What is the formula for speed? S = d / t

12) Argelio walked to school in 30 minutes. His school is 60 kilometers away. What was his average speed?

2   km per minute

13) What is the average speed of a plane that flies 1,500 miles in 10 hours?

150    mph

Learning Goal 4: Graphs of Motion (6.8D)

14) How far had the battery rolled after 4 seconds?

~ 50 meters

15) What was the average speed of the battery?

20 mps

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Learning Goal 5: Force and Acceleration (6.8D)

22) What is the difference between the formula for speed and the formula for acceleration?
Speed = d/t
Acceleration = f/m or (vf - vi) / t

23) Give three examples of acceleration, using all three things that a physicist considers acceleration.
· moving
· changing speed
·  turning

24) Which is not an example of acceleration?

a)    A falling object increasing speed as it falls
b)   Running a lap in a circle around the PE fence
c)    Changing velocity from 5 m/s to 3 m/s
d)   Running forward at a rate of 8 miles per hour

25) Find the acceleration of the car:
A Lamborghini goes from 10 m/s to 26 m/s in 2 seconds.

Formula: Acceleration = (vf-vi)/t
Solve:
8   mps^2

26) A mover is putting 96 newtons of force on a box. The box weighs 8 kilograms. At what rate will it accelerate?
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 Known: f=96 m = 8 Formula:  a=f/m Unknown:  acceleration Solve: 12 mps^2

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Formulas: f = m x a;  a = f ÷ m

27) According to Newton’s Second Law, you make a car more difficult to accelerate if:
a)    You give it a more powerful engine
b)   You construct it out of a less heavy material
c)    You put more people in it

Learning Goal 6: Newton’s Laws in Action

28) Draw a diagram showing force pairs and write an action and reaction for the following scenarios.

Example: Rocket blasts off.                                                                          Diagram:

Action: Rocket pushes up through the air.
Reaction: Gravity pulls down.

Circle the law that the scenario is showing in action. On the test, you will have to explain, too. J

A person not wearing their seatbelt flies out of the front window of a car when it hits a telephone pole.

Law:                1st                    2nd                   3rd

A ball bounces up when it pushes down on the ground.

Law:                1st                    2nd                   3rd

A swimmer swims by pushing backwards on the water.

Law:                1st                    2nd                   3rd

A big truck also needs a bigger engine in order for it to accelerate quickly.

Law:                1st                    2nd                   3rd