Download Unit 5 Review Packet

Name: ________________________
Class: ____________________________
Date: ________________________
Unit 5: Force and Motion
Unit 5 Review Packet
TEKS:
 6.8B – Identify and describe the changes in position, direction, and speed of an object when acted upon by unbalanced forces.

6.8C – Calculate average speed using distance and time measurements.

6.8D – Measure and graph changes in motion.

6.8E – Investigate how inclined planes and pulleys can be used to change the amount of force used to move an object.
The TEKs I am strong in are: ____________________________________________________________________________________
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The TEKs I struggle with are: ____________________________________________________________________________________
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My study plan for the unit 5 test is: ______________________________________________________________________________
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6.8B: Unbalanced/Balanced Forces
Vocabulary:
Force: A ____________________________ or _________________________ on an object.
Motion: The change in ___________________________ of an object in relation to a _________________________________ point.
Newton: The unit of measurement for ___________________________________________.
Balanced Forces:
1.
Briefly describe the effect balanced forces have on a resting object. _______________________________________________________________________________
____________________________________________________________________________________________________________________________________________________________
____________________________________________________________________________________________________________________________________________________________
2.
Briefly describe the effect balanced forces have on a moving object. ______________________________________________________________________________
____________________________________________________________________________________________________________________________________________________________
____________________________________________________________________________________________________________________________________________________________
3.
What is the net force of an object that has balanced forces acting on it? __________________________________________________________________________
Unbalanced Forces:
1.
Briefly describe the effect unbalanced forces have on a resting object. _____________________________________________________________________________
2.
____________________________________________________________________________________________________________________________________________________________
____________________________________________________________________________________________________________________________________________________________
3.
Briefly describe the effect unbalanced forces have on a moving object. ____________________________________________________________________________
4.
____________________________________________________________________________________________________________________________________________________________
____________________________________________________________________________________________________________________________________________________________
5.
What is the net force of an object that has unbalanced forces acting on it? ________________________________________________________________________
Name: ________________________
Class: ____________________________
Date: ________________________
Practice Questions:
1.
2.
When an unbalanced force acts on an object, there is a
change only in the _______________________________ or
___________________________ of the object.
a. Mass; speed
b. Speed; direction
c. Position; mass
d. Direction; mass
What force is needed for this box to reach equilibrium?
3.
4.
a.
b.
c.
d.
0N
10 N
11 N
12 N
What force is needed for this box to move to the left?
a. 0 N
b. 10 N
c. 11 N
d. 12 N
A wagon is pulled toward the left for 2 minutes. The wagon
has a mass of 1.1 kg. For 30 seconds, the wagon is pulled at a
constant velocity of .78 m/s. What must be true for the net
force acting on the wagon for those 30 seconds?
a. The net force is equal to 0 N.
b. The net force is greater than 0 N.
c. The net force is less than 0 N.
d. None of these.
6.8C: Calculate average speed using distance and time.
Vocabulary:
Speed: The __________________________________ an object travels in a given amount of ______________________________________.
Distance: How _______________________ an object travels.
Time: How _________________________ an object travels a certain distance.
Formula for speed:
Steps to solve speed equations:
1.
2.
3.
4.
5.
Determine what variable they’re solving for – speed, distance, or time?
Write the correct formula for what they’re solving for.
Plug in the numbers into the formula.
Calculate using the correct operation.
Re-write the answer with the correct units.
Practice Problems: Show all your work and label with the correct units!
1.
2.
An object travels 18 meters in 3 seconds. What is the
average speed?
An airplane traveled 4800 kilometers in 6 hours. What
was its average speed?
3.
A soccer ball rolls 10 meters in 20 seconds. What is the
average speed of the ball?
Name: ________________________
𝑆𝑝𝑒𝑒𝑑 =
Class: ____________________________
Date: ________________________
4.
What is the average speed of the object from 0-10
seconds?
5.
At what point is the object at rest?
6.
What is the average speed of the object from 12-16
seconds?
∆𝐷
𝐷2 − 𝐷1
=
∆𝑇
𝑇2 − 𝑇1
Use the graph to answer questions 3-5.
6.8D: Measure and graph changes in motion.
Key concepts:

What kind of graph do we use to represent distance v. time? ______________________________________________________

What variable is placed on the y-axis? ____________________________________________

What variable is placed on the x-axis? ____________________________________________

Distance v. Time graphs do not show a change in _________________________________________________.
DIRECTIONS: Draw the following situations on a distance v. time graph.
An object moving away from a reference point
3.
An object at rest
DISTANCE
DISTANCE
1.
TIME
TIME
An object moving toward a reference point
4.
An object traveling faster than another object
DISTANCE
DISTANCE
2.
TIME
TIME
Name: ________________________
Class: ____________________________
6.
Date: ________________________
Alex is skateboarding at a constant speed away from his
house. As he comes to a steep upward hill, he begins to move
a little more slowly. What would his motion look like on a
distance v. time graph?
DISTANCE
Students are doing a lab experiment in which they roll a ball
down a ramp. They notice that the ball starts rolling slowly
but then speeds up down the ramp. What would this look
like on a distance time graph? (hint: curve the line)
DISTANCE
5.
TIME
TIME
7.
How would you describe the motion of the object shown in
the graph?
6.8E: Simple machines (Inclined planes and Pulleys)
Key Concepts:

Simple machines make work _______________________________________ but do not change the amount of work need to be done.

All simple machines transfer _______________________________________.

Some simple machines change the ______________________________ or ____________________________________ of the force.
Inclined Planes:

How do inclined planes reduce the amount of force needed to move an object? __________________________________________________________________
____________________________________________________________________________________________________________________________________________________________

What is the downside to using an inclined plane to move an object? ______________________________________________________________________________
____________________________________________________________________________________________________________________________________________________________
Name: ________________________
Class: ____________________________
Date: ________________________
Pulleys:

What are the two kinds of pulleys? _______________________________________ and _________________________________________.
Fixed Pulleys

A fixed pulley does not ________________________________________.

A fixed pulley changes the _____________________________________ of the force but does not reduce the amount of force needed to lift the object.

The _________________________ amount of force is needed to lift an object when using a fixed pulley.
Movable Pulleys

A movable pulley is a pulley that _______________________________.

When using a movable pulley, it only takes ____________________________ as much force to lift the load. However, you must pull the rope twice
as ____________________________ in order to make it move half the distance.
Practice Questions:
1.
Which of the following inclined planes would require the
least amount of force to lift a box?
4.
How much force is needed to lift a 150 N load when using a
movable pulley system?
5.
Examine the picture below. How does the use of a ramp help
the man lift the box into the truck?
a.
b.
c.
d. They all require the same amount of force.
Explain your answer:
2.
The pulley shown below is used to change the
__________________ of the force used to lift an object.
a.
b.
3.
If the pulley above was lifting a 75 N force, how much force
would be needed to lift it?
c.
d.
The ramp increases the amount of force required to
move the box.
The ramp decreases the amount of distance the box
must travel.
The ramp decreases the amount of effort required
to move the box.
The ramp makes the box weigh less and require
less force to move.