1.what is a force? page #:_____ paragraph #: ___ page #:_____ paragraph #: ___ answer: answer: force...
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1.1. What is a What is a ForceForce??
Page #:_____ Paragraph Page #:_____ Paragraph #: ___#: ___
AnswerAnswer::• Force is push or pullForce is push or pull
Write an Example :Write an Example :• Throwing a baseballThrowing a baseball
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2. 2. The combination of The combination of all all the forcesthe forces acting on an acting on an
object is called?object is called?
Page #:_____ Page #:_____ Paragraph #:___Paragraph #:___
AnswerAnswer::• The The Net ForceNet Force
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3. When 3. When 2 forces2 forces cancel cancel each other out and they each other out and they don’t change the object’s don’t change the object’s velocity, they are called?velocity, they are called?
Page #:____ Paragraph Page #:____ Paragraph #:____#:____
AnswerAnswer::
BalancedBalanced Forces Forces
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4. 4. When the forces are When the forces are BalancedBalanced,,
the the net forcenet force is is??
Page #:______ Paragraph Page #:______ Paragraph #:____#:____
AnswerAnswer::
The net force is The net force is zerozero
Object’s speed/velocity Object’s speed/velocity didn’t changedidn’t change
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5. If the forces on an 5. If the forces on an object are object are UnbalancedUnbalanced, ,
the objects velocity the objects velocity changeschanges....
Page #:_____ Page #:_____ Paragraph #:___Paragraph #:___
T or FT or F
AnswerAnswer::
TrueTrue
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6. Which 6. Which ItalianItalian scientist scientist before Isaac Newton before Isaac Newton
understood how forces understood how forces work?work?
Page #:____ Page #:____ Paragraph #:___Paragraph #:___
AnswerAnswer::• Galileo GalileiGalileo Galilei
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77. Describe in-full . Describe in-full Newton’s First Law of Newton’s First Law of
Motion:Motion: Page #:______ Paragraph #:____Page #:______ Paragraph #:____
AnswerAnswer::• If the If the net forcenet force on an object is on an object is
zerozero,, the object will the object will remainremain at at restrest,, or if it’s moving, it will or if it’s moving, it will continue movingcontinue moving in straight in straight line at line at constantconstant speed. speed.
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8. What is 8. What is FrictionFriction?? Page #:_____ Paragraph Page #:_____ Paragraph #:_____#:_____
AnswerAnswer::• The force that brings The force that brings
nearly everything to a nearly everything to a
STOP!!STOP!! Resists sliding between Resists sliding between
2 objects2 objects
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9. 9. Give example of how Give example of how FrictionFriction works works..
Page #:_____ Paragraph #:_____Page #:_____ Paragraph #:_____
Answer:Answer:• Friction Friction will eventually bring will eventually bring
youryour
skateboard to a stop, unless you
keep pushing on it… keep pushing on it…
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10.10.What do the different What do the different types of Frictiontypes of Friction have in have in
common? common? ((Reading CheckReading Check))
Page #:____ Paragraph #:___Page #:____ Paragraph #:___
AnswerAnswer::• The The Frictional ForcesFrictional Forces always always
try try
to prevent one object from to prevent one object from slidingsliding
on the other object.on the other object.
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11. What causes 11. What causes Static Static FrictionFriction??
Page #:_____ Paragraph #:___Page #:_____ Paragraph #:___ AnswerAnswer::
• It is caused by the It is caused by the attraction attraction between the atoms between the atoms on the two on the two surfaces that are in contact.surfaces that are in contact.
• The The smoothersmoother the surfaces the the surfaces the less attraction between the less attraction between the atomsatoms!!!!
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11. What causes 11. What causes Static Static FrictionFrictioncont…….cont…….
• Static Friction prevents an object at rest from moving when a force is applied
12.12.Static FrictionStatic Friction acts on acts on an an
object at rest.object at rest. Page #:_____ Page #:_____ Paragraph #:_____Paragraph #:_____
True or FalseTrue or False
AnswerAnswer::• TrueTrue
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13. What does 13. What does Sliding Sliding FrictionFriction do? do?
Page #:____ Paragraph Page #:____ Paragraph #:____#:____
AnswerAnswer::• Sliding friction Sliding friction slows slows
down an object that down an object that
slidesslides
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14. What causes 14. What causes Rolling Rolling FrictionFriction??
Page #:_____ Paragraph #:_____Page #:_____ Paragraph #:_____
AnswerAnswer::• Rolling friction Rolling friction occurs when occurs when
an object rolls across a surface.an object rolls across a surface.• Example:Example:
Bicycle wheel rolling Bicycle wheel rolling
on the groundon the ground
a grounda ground
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15. Which 15. Which Frictional Frictional ForceForce is is strongerstronger??
Page #:______ Paragraph Page #:______ Paragraph #:____#:____
A.A. Rolling FrictionRolling Friction between wheels between wheels
and groundand ground
B. B. Sliding FrictionSliding Friction between box between box
and groundand ground• AnswerAnswer: :
B – B – Sliding FrictionSliding Friction
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Review questionsReview questions1. 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 questionsReview questions4.4. What is the What is the Net forceNet force when when ForcesForces
areare
BalancedBalanced??
AnswerAnswer: Net force is “: Net force is “Zero”Zero”
Object stays where it Object stays where it is!!!!!!is!!!!!!
Both boys are using sameBoth boys are using same
Force or pushing equally.Force or pushing equally.
The The DOOR DOESN’TDOOR DOESN’T
MOVEMOVE!!!!!!!!!!!!!!
Review questionsReview questions5.5. What happens when What happens when ForcesForces are are
UnbalancedUnbalanced??
AnswerAnswer: : UnbalancedUnbalanced Forces are Forces are not not
equal and the object equal and the object will move!!!will move!!!
The boy on the left is usingThe boy on the left is using
greater forcegreater force, therefore he is, therefore he is
pushing the door towardpushing the door toward
the boy on the right!!!the boy on the right!!!
Review questionsReview questions
6.6. What are the 3 types of What are the 3 types of FrictionFriction
or or Frictional forcesFrictional forces??
Answer:Answer:
StaticStatic friction friction
SlidingSliding friction friction
RollingRolling friction friction
Review questionsReview questions7. How is Force measured?Answer: In a unit called Newton8. What is a Newton?Answer:
One Newton (symbol NN) is the forcethat will give an object whose is
mass 1kilogram an acceleration of 1 meter
persecond squared.
N=1 kg·m/s²N=1 kg·m/s²
Review questionsReview questions9. 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 = 2N10N – 8N = 2N
Review questionsReview questionsStudy the diagram carefully and answer the questions
10. Are the 10. Are the ForcesForces on on the box the box BalancedBalanced or or UnbalancedUnbalanced?? Answer:
Unbalanced 11. What is the Net Force on the box?
Answer: 45N – 30 N = 15N
Net force is 15NNet force is 15N
45N
30NWe
stEast
Review questionsReview questions
12. In which direction did the box move? Answer:
The box moved East
45N 30N
West East