Download What is a Force? Page #:______ Paragraph #: ______

1. What is a Force?
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Answer:
• Force is push or pull
Write an Example :
• Throwing a baseball
2. The combination of all the
forces acting on an object is
called?
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Answer:
• The Net Force
3. When 2 forces cancel each other
out and they don’t change the
object’s velocity, they are called?
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Answer:
Balanced Forces
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4. When the forces are Balanced,
the net force is?
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Answer:
The net force is zero
Object’s speed/velocity didn’t
change
5. If the forces on an object are
Unbalanced, the objects velocity
changes..
3
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T or F
Answer:
True
6. Which Italian scientist before
Isaac Newton understood how
forces work?
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Answer:
• Galileo Galilei
7. Describe in-full Newton’s First
Law of Motion:
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Answer:
• If the net force on an object is zero,
the object will remain at rest, or if
it’s moving, it will continue moving
in straight line at constant speed.
8. What is Friction?
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Answer:
• The force that brings
nearly everything to a
STOP!!
 Resists sliding between
2 objects
9. Give example of how
Friction works.
1
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Answer:
• Friction will eventually bring your
skateboard to a stop, unless you
keep pushing on it…
10. What do the different types of
Friction have in common?
(Reading Check)
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Answer:
• The Frictional Forces always try
to prevent one object from sliding
on the other object.
11. What causes Static Friction?
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Answer:
• It is caused by the attraction
between the atoms on the two
surfaces that are in contact.
• The smoother the surfaces the less
attraction between the atoms!!
11. What causes Static Friction
cont…….
• Static Friction prevents an object at
rest from moving when a force is
applied
12. Static Friction acts on an
object at rest.
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True or False
Answer:
• True
13. What does Sliding Friction do?
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Answer:
• Sliding friction slows
down an object that
slides
14. What causes Rolling Friction?
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Answer:
• Rolling friction occurs when
an object rolls across a surface.
• Example:
Bicycle wheel rolling
on the ground
15. Which Frictional Force is
stronger?
2
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A. Rolling Friction between wheels
and ground
B. Sliding Friction between box
and ground
• Answer:
B – Sliding Friction
Review questions
1. How would you describe a Force?
Answer: Push or a Pull
2. What is Net Force?
Answer: Combination of all the Forces
3. Describe what it means when forces are
Balanced?
Answer: The forces acting on the object
are equal. Object does not move.
Review questions
4. What is the Net force when Forces are
Balanced?
Answer: Net force is “Zero”
Object stays where it is!!!!!!
Both boys are using same
Force or pushing equally.
The DOOR DOESN’T
MOVE!!!!!!!
Review questions
5. What happens when Forces are
Unbalanced?
Answer: Unbalanced Forces are not
equal and the object will move!!!
The boy on the left is using
greater force, therefore he is
pushing the door toward
the boy on the right!!!
Review questions
6. What are the 3 types of Friction
or Frictional forces?
Answer:
Static friction
Sliding friction
Rolling friction
Review questions
7. How is Force measured?
Answer: In a unit called Newton
8. What is a Newton?
Answer:
One Newton (symbol N) is the force
that will give an object whose is mass 1
kilogram an acceleration of 1 meter per
second squared.
N=1 kg·m/s²
Review questions
9. In a tug of war, one student is pulling on a
rope with a force of 10N and the other student
with 8 N. What is the Net force on the rope?
Or, the actual amount of force pulling on the
rope?
Answer:
It is the difference between
the stronger and the weaker
force
10N – 8N = 2N
Review questions
Study the diagram carefully and answer the
questions
10. Are the Forces on
45N
30N
the box Balanced
West
East
or Unbalanced?
Answer:
Unbalanced
11. What is the Net Force on the box?
Answer:
45N – 30 N = 15N
Net force is 15N
Review questions
45N
30N
West
East
12. In which direction did the box move?
Answer:
The box moved East