Download Newton`s Laws Notes Packet - Blanks PDF

Vocabulary
Term
Definition
Force
Inertia
Newton
Net Force
Newton’s 1st Law
Newton’s 2nd Law
Newton’s 3rd Law
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Newton’s 1st Law of Motion
Every body persists in its state of rest or of uniform motion in a straight line unless it is
compelled to change that state by unbalanced forces impressed on it. ~ISAAC NEWTON
The principle we describe as Newton’s first law was actually first discovered by
Galileo. (Many of Newton’s “discoveries” originated with people other than Sir
Isaac.) Before Galileo, the explanation for natural motion was the one put forth by
Aristotle. Aristotle theorized that things move to find their natural place in the
universe and come to rest when they get there.
Galileo, on the other hand, proposed that objects maintain their state of motion: If
they are at rest, they remain at rest unless acted on by an external force. Easy
enough. But Galileo went on to say that objects moving in a straight line with
constant speed (constant velocity, in other words) remain moving in a straight line
with constant speed, unless acted upon by an external force.
“That’s so dumb,” charged Galileo’s many antagonists (Galileo had a knack for
making enemies), “you’re saying that if I set a brick into motion on a tabletop, it will
maintain constant velocity? Get outta town!”
“Of course not, propeller-heads!” Galileo explained. “In the case of the brick, a
frictional force acts on the brick to bring it to rest. But consider an experiment I’ve
done:”
Of course, the ball does not continue forever. Air resistance and rolling friction forces
slow the ball to a stop. But if a ball were given a push in deep space, it would travel
an exceedingly long distance before being acted on by external forces. To understand
a concept like this we need to “undress nature.” We must look past superficial
complexity to see the simple characteristics of nature. Once the fundamental
properties are understood, we can take into account other, more complex factors.
The simple characteristic of nature that Newton points out is that objects are “lazy.”
If they are at rest, they have no “desire” to get up and move. If they are to move,
something else will have to kick them in the rear (providing the unbalanced external
force). If they are moving at a constant velocity, they will continue at constant
velocity. If a force pushes them along, they will go faster. If a force pushes against
them, they will slow down. The “laziness” of matter is called inertia. Formally,
inertia is defined as the resistance a body offers to changes in its state of
motion and applies to moving and non-moving objects.
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Newton’s 1st Law of Motion
Newton’s 1st Law of motion
Main Ideas
is also know as the
law of
Definition of
inertia:
Unless acted upon
by an
Applying Newton’s 1st Law of
motion
Explain according to Newton’s 1st law of motion what would happen to the person in the car
below if they crashed into the wall using the terms inertia, state of motion, and unbalanced
NEWTON’S FIRST LAW OF MOTION (aka: _______________________________)
force.
States:
An Object ____________________________________________________________
____________________________________________________________________
____________________________________________________________________
___________ is the property of an object that resists changes in motion.
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Class Work
1. Which has more inertia a bowling ball or a golf ball? __________________
2. Objects with more mass have more ____________ and are more __________
____________ to changes in their motion.
3. Mac and Tosh are arguing in the cafeteria. Mac says that if he flings the Jell-O
with a greater speed it will have a greater inertia. Tosh argues that inertia does not
depend upon speed, but rather upon mass. Who do you agree with? Explain why.
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
4. Fred spends most Sunday afternoons at rest on the sofa, watching pro football
games and consuming large quantities of food. What effect (if any) does this
practice have upon his inertia? Explain.
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
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Notes – Newton’s Second Law
John and Joe have a grocery cart race. John pushes a loaded grocery cart; Joe pushes an
empty grocery cart. Joe wins the race. Why?
John
Joe
Joe and his little brother Junior have a grocery cart race. Joe wins the race. Why?
Joe
Junior
1. When a grocery cart is pushed by a person, a(n) __________
__________ acts on the cart and the cart __________.
2. The acceleration of an object is directly proportional to the net force
acting on it. This means that, as the net force acting on the object
increases, the acceleration of the object __________.
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Newton’s 2nd Law of Motion states:
The acceleration of an object is directly proportional to the net force acting on the object and
inversely proportional to the object’s mass.
2nd law
abbreviated using
symbols:
∑F = ma
∑F = sum of the forces
m = mass
a = acceleration
Newton’s 2nd law relates the net force on an object, the mass of the object, and
acceleration.
 It states that the stronger the net force on an object,
__________________________
 If twice the net force is applied, the acceleration will be _______________ as
great.
 The acceleration of an object is _____________________ proportional to the net
applied force and __________________________ proportional to the mass.
∑F
a
m
NEWTON’S 2ND LAW
Formula
Want to find
What you know
acceleration (a)
force (F) and mass (m)
force (F)
acceleration (a) and mass (m)
mass (m)
acceleration (a) and force (F)
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Formula
Newton’s 2nd Law
No Acceleration
Net Force
Net force is
_____________.
Same Direction
Objects are at _____
or moving with
constant
__________.
Opposite Direction
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NEWTON’S SECOND LAW
Formula
Want to find
What you know
acceleration=Force/mass
force (F) and mass (m)
Force =mass x acceleration
acceleration
(a)
force (F)
acceleration (a) and mass (m)
Mass = Force/ acceleration
mass (m)
acceleration (a) and force (F)
F
a
m
Class Work
1. A 1650 kg car accelerates at a rate of 4.0 m/s2. How much force is the car's engine
producing?
Looking For
Given
Relationship
Solution
2. A tennis ball, 0.314 kg, is accelerated at a rate of 164 m/s2 when hit by a
professional tennis player. What force does the player's tennis racket exert on the
ball?
Looking For
Given
Relationship
Solution
3. A crate is dragged across an ice covered lake. The box accelerates at 0.08 m/s2
and is pulled by a 47 N force. What is the mass of the box?
Looking For
Given
Relationship
Solution
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Group Work
1. What is the rate of acceleration of a 2,000-kilogram truck if a force of 4,200 N is
used to make it start moving forward?
Looking For
Given
Relationship
Solution
2. What is the acceleration of a 0.30 kilogram ball that is hit with a force of 25 N?
Looking For
Given
Relationship
Solution
3. How much force is needed to accelerate a 68 kilogram-skier at a rate of 1.2
m/sec2?
Looking For
Given
Relationship
Solution
4. What is the mass of an object that requires a force of 30 N to accelerate at a rate
of 5 m/sec2?
Looking For
Given
Relationship
Solution
5. What is the force on a 1,000 kilogram-elevator that is falling freely under the
acceleration of gravity only?
Looking For
Given
Relationship
Solution
6. What is the mass of an object that needs a force of 4,500 N to accelerate it at a
rate of 5 m/sec2?
Looking For
Given
Relationship
Solution
7. What is the acceleration of a 6.4 kilogram bowling ball if a force of 12 N is
applied to it and it experiences a 4-N frictional force?
Looking For
Given
Relationship
Solution
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HomeWork (10 points)
1. What is the rate of acceleration of a 1,000-kilogram truck if a force of 4,200 N is
used to make it start moving forward?
Looking For
Given
Relationship
Solution
2. What is the acceleration of a 0.30 kilogram ball that is hit with a force of 50 N?
Looking For
Given
Relationship
Solution
3. How much force is needed to accelerate a 68 kilogram-skier at a rate of 1.2
m/sec2?
Looking For
Given
Relationship
Solution
4. What is the mass of an object that requires a force of 30 N to accelerate at a rate
of 5 m/sec2?
Looking For
Given
Relationship
Solution
5. What is the mass of an object that needs a force of 4,500 N to accelerate it at a
rate of 5 m/sec2?
Looking For
Given
Relationship
Solution
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Newton’s 3rd Law
ACTION
states that
Forces are equal in
Forces are opposite in
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REACTION
Newton’s 2nd Law of Motion
Physics
Introduction
Consider two students, of different masses on low friction carts able to pull on each other
with a rope.
Consider the force that each student exerts on the other during the pull of the rope. What
motion results in each case? Does it depend on the mass of the students? For each
situation described below, predict what you think will happen to each person. You will
then perform the action described and compare the actual result to your prediction. Draw
and carefully label a diagram for each of the students during each interaction. Use arrows
to indicate which direction the force is acting.
Directions
Student 1 should pull on the rope while student 2 holds the rope. How far will each
student move? Does your answer depend on the mass of each student? Is your answer
related to the force that each student exerts? Explain.
Prediction:
Result:
Student 1
Student 2
Student 2 should pull on the rope while student 1 holds the rope. How far will each
student move? Does your answer depend on the mass of each student? Is your answer
related to the force that each student exerts? Explain.
Prediction:
Result:
Student 1
Student 2
Both students should pull on their respective scales. How far will each student move?
Does your answer depend on the mass of each student? Is your answer related to the force
that each student exerts? Explain.
Prediction:
Result:
Student 1
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Student 2
Introduction:
Newton’s 1st Law – An object in motion will stay in motion and an object at rest will stay
at rest unless acted on by an outside force (such as friction and air resistance).
Newton’s 2nd Law – Force, mass, and acceleration are all related. Force = mass x
acceleration
Newton’s 3rd Law – Every action has an equal and opposite reaction.
Materials:
Hovercraft, Stopwatch, Meter Stick, Weights or Heavy Books, Skateboard, rolling chair,
or anything that rolls
Procedure:
1. Begin by having one person sit on the cart. Have another person give the sitting
person a light push. Measure how far this person rolled and record below.
2. Have this same person sit on the Hovercraft while it is running. Have the other
person give the sitting person the same light push. Measure how far this person
rolled and record below.
3. Next, have a person sit on the Hovercraft and give him or her a push. Time how
long the person takes to come to a stop.
4. Now place weights or heavy books on the Hovercraft with the same person and
give him or her the same amount push as before. Again measure the time it takes
for the person to come to a s stop and record the results below.
5. Have one person sit on the hovercraft and the other sit on the rolling chair or
skateboard. Have each person put their hands flat against each other and push off.
Notice what happens to each person.
Data Table:
Distance student on cart rolled
=
__________
Distance student on hovercraft moved =
__________
Time it took for the student on hovercraft to stop =
__________
Time it took for the student on hovercraft with weights to stop =
__________
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Analysis:
Directions: Answer the following questions on a separate sheet of paper.
1. Newton’s 1st law says an object in motion will stay in motion and an object at rest
will stay at rest unless acted on by an outside force. Why did the student on the
rolling chair or skateboard stop rolling so soon after he or she was pushed? Why
did the hovercraft eventually come to a stop also? Does this disprove or prove
Newton’s 1st Law? Explain your answer.
2. Using Newton’s 2nd Law, explain the difference in time for the student to stop
with and without weights. How was the student’s acceleration affected? How
does time relate to acceleration?
3. When the 2 students pushed off each other, what happened? Why did this happen
and how does this relate to Newton’s 3rd Law?
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Project - The Inertia Car
Due:
Weight: 50 points
Individual: You are on your own!
Objective
Construct a vehicle to roll down a ramp and down a hallway using only the inertia of the
vehicle as the source of energy.
Materials Disqualified
 Any body of a commercial toy vehicle. (You ARE permitted to cannibalize any
other parts from a toy).
Synopsis
You are to construct a vehicle using any materials of your choosing. Your vehicle must
roll down the hallway in front of room 303, as far as possible. The only source of energy
permitted is the inertia of the vehicle. That means, no motors, rubber bands, chemicals,
projectiles, etc. The vehicle will be launched from the top of a 1.96-m long wooden ramp
, set at a 20 angle with respect to the horizontal. The ramp, which does not have side
rails is approximately 28.5-cm wide. (you have the option of rolling your vehicle down a
different ramp that is 1.22 meters long and 20.5-cm wide that has guard rails, but you can
only roll your vehicle down one ramp or the other). Finally, your vehicle must be
seasonally decorated to qualify.
Rules
1. Vehicles may not utilize the bodies of commercial toy vehicles (ex: car, train,
planes, etc)
2. Vehicle may not exceed the following dimensions: Width  28.5 or 20.5-cm;
Height  30cm; length  30 cm.
3. The vehicle must have a mass  0.5 kg to qualify.
4. The vehicle must be seasonally decorated to qualify.
5. You must construct the vehicle. You are not permitted to purchase kits such as
pinewood derby racers.
6. Your vehicle must resemble a car, truck, or motorcycle (ie minimum of 2 wheels)
and you are not permitted to add masses to your car. If the body and wheels of
your car do not add to at least 500 grams you will need to brainstorm how you can
qualify for the minimum mass requirement. You can add passengers to your
vehicle.
7. Points will be awarded for the mass of the vehicle. The lightest vehicle in the
class will receive 6 points. Other vehicles will be grouped into 3 groups: Light =
5 pts; Medium = 3 pts; Heavy = 1 pt. The heaviest vehicle in the class receives
zero pts.
8. Vehicles traveling a minimum distance of 1-m earn 10 points. Shorter runs
receive zero points.
9. Only one trial is permitted.
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10. In the event that the vehicle crashes/touches into the side walls of the hallway, the
point of collision will serve as the final position of the vehicle.
11. The vehicle travels far for its mass. The vehicle with the largest ratio of
distance/mass will receive 6 points. Other vehicles will be grouped into 3 groups,
awarded points as follows: Large = 5 pts; Medium = 3 pts; Small = 1 pt. The
smallest ratio in the class receives zero pts.
Scoring
Vehicle is constructed according to the
rules.
Vehicle mass
Vehicle travels minimum distance
requirement
Vehicle travels far for its mass
30 pts
Up to 6 points
10 points
Up to 6 points
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Performance Assessment
General Physics
You are a skateboarder who has been asked to compete at the state x-games by your
skater buddies and will be wowing the world with your fearless feats. When you take the
x-games cup, your buddies want explanations for your gravity defying performance.
Write an e-mail describing the stunts used during your competition. Explain how you
used Newton’s laws of motion to ace each stunt. Include five stunts identifying at least
one Law per stunt. All three laws must be used.
PERFORMANCE ASSESSMENT: EXTREME GAMES
PERFORMANCE LEVELS
CRITERIA
FOR
SUCCESS
Number of
Stunts
Explained
Accuracy of
Scientific
Terms
Newton’s 1st
Law
Newton’s
2nd Law
Newton’s 3rd
Law
5
Tony
Hawk
5 fully
explained
4
Ranked
4 fully
explained
No mistakes 1 mistake
Fully
explained
and
relevant to
stunt(s)
Fully
explained
and
relevant to
stunt(s)
Fully
explained
and
relevant to
stunt(s)
Partially
explained
and
relevant to
stunt(s)
Partially
explained
and
relevant to
stunt(s)
Partially
explained
and
relevant to
stunt(s)
3
Pretty
Decent
2
Better
keep the
pads
1
Crash and
Burn
3 fully
explained
2 fully
explained
1 fully
explained
2 mistakes
3 mistakes
4 mistakes
Explanation
incorrect or
not relevant
to stunt(s)
Explanation
incorrect or
not relevant
to stunt(s)
Explanation
incorrect or
not relevant
to stunt(s)
Explanation
incorrect
and not
relevant to
stunt(s)
Explanation
incorrect
and not
relevant to
stunt(s)
Explanation
incorrect
and not
relevant to
stunt(s)
Explanation
missing
Explanation
missing
Explanation
missing
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