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Jeopardy
PHY101 Chapter Two Review Newtons Laws
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Study of Newtons Laws
Basics of Force Newtons Laws Analyzing Forces Circular Motion Resistive Forces Potpourri
100 100 100 100 100 100
200 200 200 200 200 200
300 300 300 300 300 300
400 400 400 400 400 400
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Basics of Force100
What is Force?
ANSWER
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Basics of Force200
What is the equation for force? What are the
units in the 3 systems?
ANSWER
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Basics of Force300
What is weight?
ANSWER
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Basics of Force400
What is momentum?
ANSWER
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Newton's Laws 100
What is mass?
ANSWER
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Newton's Laws 200
What is Newtons First Law?
ANSWER
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Newton's Laws 300
What is Newtons 2nd Law?
ANSWER
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Newton's Laws 400
What is Newtons 3rd Law?
ANSWER
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Analyzing Forces 100
What is a free body diagram?
ANSWER
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Analyzing Forces 200
What is a normal force?
ANSWER
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Analyzing Forces 300
What is Hookes Law?
ANSWER
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Analyzing Forces 400
A child stands on a bathroom scale while riding
in an elevator. The child's weight when the
elevator is not moving is 200 N. What is the
childs mass in kg? What does the scale read
(tension T) when the elevator accelerates upward
at 1.00 m/s2?
ANSWER
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Circular Motion 100
If an object moves in a circle, what kind of
force acts the centripetal force?
ANSWER
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Circular Motion 200
What is the equation for centripetal (radial)
force?
ANSWER
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Circular Motion 300
What is Newtons Law of Gravity?
ANSWER
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Circular Motion 400
What is the acceleration due to the earth's
gravity at a distance of one earth radius above
the earth's surface? a. 2.5 m/s² b. 5 m/s² c. 10
m/s² d. 20 m/s²
ANSWER
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Resistive Forces 100
What is a drag force?
ANSWER
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Resistive Forces 200
What is friction?
ANSWER
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Resistive Forces 300
Name two types of friction?
ANSWER
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Resistive Forces 400
A horizontal force of 640 N is applied to a car
with a mass of 1600 kg. What is the acceleration
of the car if the coefficient of rolling friction
is 0.01? a. 0.02 m/s² b. 0.03 m/s² c. 0.2
m/s² d. 0.3 m/s²
ANSWER
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Potpourri 100
A 9.00-kg object is moving in a circle with a
constant speed of 45.0 m/s. If the circular
path has a radius of 20.0 m, what is the net
force on the object?
ANSWER
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Potpourri 200
What are the conditions for simple harmonic
motion?
ANSWER
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Potpourri 300
Before going to the beach, you check the position
of the moon. Why?
ANSWER
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Potpourri 400
The average orbital speed of Mars is 2.41 x 104
m/s. If the radius of Mars's orbit is 2.28 x
1011 m, how long does it take Mars to complete
one orbit?
ANSWER
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Basics of Force100Answer
What is Force? Force is a push or a pull.
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Basics of Force200Answer
What is the equation for force? Force F ma
mDv/Dt SI unit 1 kgm/s² 1 Newton 1
N cgs unit 1 gcm/s² 1 dyne Common unit
1 slugft/s² 1 lb. 1 N 105 dynes 0.2248
lbs
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Basics of Force300Answer
What is weight? Weight is the
force of gravity acting on a body. W mg where
g is local gravity
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Basics of Force400Answer
What is momentum? Momentum is mass X velocity p
mv Unit is 1 kgm/s in SI
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Newton's Laws 100Answer
What is mass? Mass is a measure of an objects
resistance to acceleration. It is a measure of
the quantity of matter in an object.
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Newton's Laws 200Answer
What is Newtons First Law? An object will
remain at rest or in motion with a constant
velocity unless acted upon by an outside force. ?
F 0 v constant a 0
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Newton's Laws 300Answer
What is Newtons 2nd Law? An object is
accelerated whenever a net external force acts on
it. The net force equals the objects mass
times its acceleration. ? F ma
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Newton's Laws 400Answer
What is Newtons 3rd Law? Forces always come in
pairs. When one object exerts a force on a
second object, the second exerts an equal and
opposite force on the first. ? F 0 F12 -F21
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Analyzing Forces 100Answer
What is a free body diagram? A free body
diagram is a force picture showing all the
forces, the net acceleration and the direction of
motion. ? Fy ma T - mg
T



a T mg ma T m(g a)

mg
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Analyzing Forces 200Answer
What is a normal force? A normal force is a
(reactive) balancing force such that ? F 0.
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Analyzing Forces 300Answer

• What is Hookes Law?
• This is a conservative spring force equation.
• F - kSx ma
• where kS Weight of spring object/stretch in
  SI units of N/m

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Analyzing Forces 400Answer
A child stands on a bathroom scale while riding
in an elevator. The child's weight when the
elevator is not moving is 200 N. What is the
childs mass in kg? m Weight/g 20.4
kg What does the scale read (tension T) when the
elevator accelerates upward at 1.00 m/s2? ? Fy
ma T - mg



T mg ma T
m(g a) 220 N

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Circular Motion 100Answer
If an object moves in a circle, what kind of
force acts the centripetal force? A real force
like tension or gravity must act as a centripetal
force and point toward the center of the circle.
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Circular Motion 200Answer
What is the equation for centripetal (radial)
force? SF centripetal mv²/r
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Circular Motion 300Answer
What is Newtons Law of Gravity? F G
m1m2/d² G 6.67 10-11 Nm²/kg²
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Circular Motion 400Answer

• What is the acceleration due to the earth's
  gravity at a distance of one earth radius above
  the earth's surface?
• 2.5 m/s² b. 5 m/s² c. 10 m/s² d. 20 m/s²
• F G Mm/d² mg
• If dnew 2d, then FNEW G Mm/(4d²) mgNEW
  mg/4
• gNEW g/4 2.45 m/s²

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Resistive Forces 100Answer
What is a drag force? A resistive force called
air resistance. Drag Force ½ CdensityAreav²
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Resistive Forces 200 Answer
What is friction? A force of resistance to
relative motion between 2 bodies or substances in
physical contact. f Coefficient of friction
Normal Force µFN
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Resistive Forces 300 Answer
Name two types of friction? Static friction no
motion Kinetic friction motion
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Resistive Forces 400 Answer
A horizontal force of 640 N is applied to a car
with a mass of 1600 kg. What is the acceleration
of the car if the coefficient of rolling friction
is 0.01? a. 0.02 m/s² b. 0.03 m/s² c. 0.2
m/s² d. 0.3 m/s² SFy 0 FN mg FN mg
15680 N fK µFN µmg 157 N SFX ma
Pull fk 640 N 157 N 483 N a
SFX /m 483 N/ 1600 kg 0.30 m/s²
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Potpourri 100Answer
A 9.00-kg object is moving in a circle with a
constant speed of 45.0 m/s. If the circular
path has a radius of 20.0 m, what is the net
force on the object? F mv²/r (9.00kg)(45
m/s)²/(20.0m) 911 N
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Potpourri 200Answer

• What are the conditions for simple harmonic
  motion?
• Motion must be periodic
• Force must cause the motion and be parallel to it.

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Potpourri 300Answer
Before going to the beach, you check the position
of the moon. Why? Low tide moon on
horizon High tide high point in sky
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Potpourri 400Answer
The average orbital speed of Mars is 2.41 x 104
m/s. If the radius of Mars's orbit is 2.28 x
1011 m, how long does it take Mars to complete
one orbit? V 2pr/T T 2pr/v 5.94 107
sec 688 days
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