Download 10_26_29_NewtonsFirstLawPacket - Elizabeth C-1

Name _______________________________________________________ Block ____________ Date ________________
Newton’s First Law of Motion
Why?
All motion on earth and throughout the universe can be explained using Isaac Newton’s
three laws of motion. They can be used to a) describe the interactions and resulting forces
between objects and b) predict the motion of objects. Forces and motion are an integral
factor in our lives from transportation safety to sports to simply walking down the street.
Examine the pictures below and follow the directions that follow.
23 N
23 N
A1. Draw force vectors (arrows) for the two forces depicted in the picture.
A2. What is the net force? ___________
A3. What kind of force is this? Circle one.
balanced
unbalanced
A4. Is there a change in motion? ______________ If so, in what direction?
10 N
20 N
B1. Draw force vectors (arrows) for the two forces depicted in the picture.
B2. What is the net force? ___________
B3. What kind of force is this? Circle one.
balanced
unbalanced
B4. Is there a change in motion? ______________ If so, in what direction?
B5. Based on Part A and B, what kind of force is required to create a change in motion?
Circle one.
balanced
unbalanced
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Examine the following comic. Fill in the blanks with the appropriate scientific terms used to
describe motion and forces. A young Albert Einstein places a soccer ball on a brick wall.
THE SOCCER BALL STAYS
_____ _____________ AND
DOES NOT MOVE BECAUSE
THERE IS NO
_____________________
FORCE ACTING UPON IT.
This comic can be read in full at:
http://Pixton.com/ic:RKERHD3D
Created by DragonRider324
C1. What was required to set the ball in motion? _______________________________________
C2. In scientific terms, a push is an example of a ____________________________.
C3. What was the initial velocity of the ball? _______________ m/s
C4. Was the velocity after the push greater than 0 m/s?
C5. Did the ball accelerate as a result of the push? ___________
Newton’s First Law
Newton’s first law states that an object at rest tends to stay at rest
and an object in motion tends to stay in motion with the same
speed and in the same direction unless acted upon by an
unbalanced force.
Another way to state this is to say that if the net forces acting on an object are
zero, then an object will continue to do what it was doing (have the same
motion). If the net force is greater than zero, then an objects motion will
change.
For example, when you are standing the force of gravity is balanced by the
force of the floor holding you up.
D1. Does the case of our soccer ball sitting on the wall follow Newton’s first law? _________
D2. After young Einstein pushed the ball, it was set in motion. According to Newton’s first
law, the ball should continue to move (stay in motion) till an unbalanced force acts on it.
You know from experience, that a soccer ball eventually comes to rest. Is an unbalanced
force acting upon the soccer ball?
Yes
No
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D3. What direction is the ball moving in? Circle one.
left
right
D4. What is the wall made of? (Think small)
D5. Does friction exist between the ball and the wall? ____________ If so, which direction?
D6. Since the ball slowly comes to a stop, what does that mean about the acceleration of the
ball? Circle one.
A. The ball has positive acceleration (it speeds up).
B. The ball has negative acceleration (it slows down).
D7. Since the ball slowly comes to a stop, what does that mean about the net force on the
ball as it rolls?
The net force is ___________________________ and acts in the _____________________ direction.
(increasing or decreasing)
(left or right)
HERE, THE BALL EVENTUALLY STOPS
ROLLING BECAUSE AN UNBALANCED
FORCE, CALLED__________________
IS APPLIED.
D8. Fill in the blanks for Newton’s first law here:
An object at rest tends to stay ______ _____________________ and an object in motion tends to
stay ______ _____________________ with the same _________________ and ________________________
unless acted upon by an __________________________ force.
D9. Explain why the ball eventually comes to a stop. Use complete, grammatically correct
sentences. Include and underline the words: motion, force, unbalanced, friction, direction.
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Another way to look at this is in terms of acceleration, which is illustrated in the
chart below. Use the chart below to answer the following questions.
E1. If forces acting on an object are balanced, what is the
resulting acceleration? _________ m/s2
E2. According to the scientific definition of acceleration.
Acceleration is a change in:
___________________________ and/or _____________________________.
E3. If an object is at rest, the velocity is: ______ m/s
E4. If an object is at rest, the acceleration is: _________ m/s2
E5. If you apply an unbalanced force to this object it will ____________. Circle ALL that apply.
change velocity
accelerate
change position
E7. A soccer ball is traveling through an area of space, where there is no friction, at a speed
of 25 m/s. If no unbalanced forces act upon it, what is its velocity after 1 minute? ______ m/s
E8. If no unbalanced forces act upon it, what is its acceleration after 1 min? ____________ m/s2
E9. Below, fill in the blanks to restate Newton’s first law in terms of acceleration.
An object at rest does not _________________________________ and an object in motion does not
___________________________________, unless an _____________________________ force acts upon it.
Use the pictures of the shopping carts to the right to answer the following questions.
Inertia: the resistance an object has to a change in its state of motion
F1. Is it easier to turn a full shopping cart or an empty one?
F2. What quantity measures the amount of matter (“stuff”) an object contains?
mass
volume
temperature
F3. The greater the ___________ of an object, the greater the ___________________________.
F4. Based on your answer to F2, why is harder to push the full cart?
F5. Describe the relationship between inertia and mass below. Circle one.
Mass is directly or indirectly related to inertia.
F6. Which has more inertia? Circle one. Explain why.
Sumo wrestler
Gymnast
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Discuss and review the key ideas of this session before attempting these questions. After
reading each question, brainstorm ideas as a group before writing your final answer.
Critical Thinking/Application Questions
G1. Suppose you were in space (far away from any opposing forces – friction or gravity, for
example) and you kicked a soccer ball. What would happen to the ball? Explain. Use
grammatically correct sentences. Include and underline the words: force, acceleration,
motion.
G2. A 2.0 kg bowling ball is moving with a speed of 4.0 m/s. How much net force is required
to keep the object moving at this velocity (assuming there is no friction)? __________ N
What is the bowling balls acceleration? ___________ m/s2. Explain. Use grammatically correct
sentences. Include and underline the words: force, acceleration, motion.
G3. Ben Tooclose is being chased through the woods by a moose which he was trying to
photograph. The enormous mass of the moose is extremely intimidating. Yet, if Ben makes
a zigzag pattern through the woods, he will be able to use the large mass of the moose to
his own advantage.
Explain this in terms of inertia and Newton’s first law of motion. Use grammatically correct
sentences. Underline and include the words: motion, change, direction, acceleration,
inertia, and mass.