Download NEWTONS LAWS

NEWTONS
L AW S
INTERACTIVE NOTES
for NEWTON’S 3 LAWS
OF MOTION
Draw the forces acting on
this thrown ball
Name_______________________________________
NEWTONS LAWS
Sir Isaac Newton—between 1665 and 1666 he developed 3 laws to describe all states of
motion. In order to understand these laws, you must first understand inertia.
Draw the forces acting on this thrown ball
Due to which force does the ball eventually fall to the ground? _________________________________
Inertia— a property of matter that says matter wants to ________________________________
____________________________________________________________________________
A. If an object is at rest, it wants to ______________________________________________
B. If an object is moving it wants to ______________________________________________
C. The more mass an object has, the ______________________ inertia it has. (Hint—Would you
have to work harder to change the position of a couch or a soccer ball at rest?)
D. Back to the thrown ball. After the player throws the ball, due to inertia, what does the ball
want to keep doing? __________________________________ Why doesn’t it? ______________
_________________________________________________________________________________
In order for an object to change its motion, what must happen?__________________________
CONGRATULATIONS! You just figured out Newton’s 1st law!
Newton’s 1st Law— “An object at rest will __________________________________________ and an
object in motion will __________________________________________ at the same speed and in the
same direction unless acted on by an _________________________________________.”
E. Some more examples of the 1st Law.
1. The rolling cart and ball.
Notice the ball is in the back of the cart before I push the cart.
When I push the cart, does the ball move? ______________________
What force caused the ball to start moving? ____________________
What happens to the ball when the cart hits the wall? ____________
Explain in terms of Newton’s 1st law why this happened by answering the questions below.
Why did the ball keep rolling once the cart stopped? _________________________________
________________________________________________________________________________
What was the unbalanced force that finally caused the ball to stop moving? _____________
2. Why do you fall forward when you stub your toe on a chair? Explain in terms (meaning use
the words in the law in your answer) of inertia and Newton’s 1st law.
3. Why do you fly forward when hitting a curb while riding a skateboard or bike? Explain in
terms of inertia and Newton’s 1st law.
4. Come up with your own example of Newton’s first law! Again- explain using inertia and
Newton’s 1st law.
Name ________________________________
NEWTON’S SECOND LAW
What is acceleration? _______________________________________________________________________
__________________________________________________________________________________________
Sir Isaac Newton did several experiments that looked at force and acceleration. These are his
observations:
A. Applying a larger net force to an object will result
in______________________ acceleration
B. If you apply equal net forces to two objects with
different masses, the one with the smaller mass will
accelerate ______________________.
C. If you want 2 objects with different masses to have
the same acceleration, the object with the larger mass
will require __________________ force.
Based on these observations, Newton came up with a law to describe acceleration.
Newton’s 2nd Law: “The acceleration of an object depends on the __________________
_____________________________ and the ______________________________________
___________________________________________________________________________
Name ____________________
MORE FROM SIR ISAAC NEWTON
Stand up and firmly push with the palm of your hand on the
EDGE of the table. (DO NOT PUSH THE TABLE FORWARD)
When I say so, stop and look at your hand. What did feel?
____________________________________________________
What do you see on your hand?___________________________
What put the indentation in your hand? ____________________
_______________________________________________________
Draw arrows representing the direction of any forces happening in this situation.
Newton’s 3rd Law of Motion --“For every action there is an equal and opposite
reaction”
What is the action in this situation? _____________________________________
What is the reaction in this situation? ___________________________________
Label them in your picture.
Whenever two objects interact with each other, they exert forces upon each other.
1. Imagine pushing on a (solid) wall (or door ) with a fairly large force, and
assume you don't break through. According to Newton's third law, the wall is
exerting an equal and opposite force back on you.
Explain this in your own words: What is the action?_________________________
_______________________________________________________________________
What is the reaction? ____________________________________________________
_______________________________________________________________________
How do you know the reaction is EQUAL to the action? ______________________
________________________________________________________________________
Gravity
pulling
person
down
2. When you sit in a chair, your body exerts a downward force on the chair and the chair exerts
an upward force on you! The chair is what keeps you from falling to the ground. It is actually
pushing you upward with a force equal to gravity pulling you down.
What is the action?________________________________________________________________
What is the reaction? ______________________________________________________________
How do you know the action is equal to the reaction? __________________________________
Think of another example like these and explain it in your own words: _____________________
Chair
pushing
up on
person
____________________________________________________________________________________
Name _____________________________________________
NEWTONS LAWS-answers
Sir Isaac Newton—between 1665 and 1666 he developed 3 laws to describe all states of
motion. In order to understand these laws, you must first understand inertia.
Draw the forces acting on this thrown ball
Due to which force does the ball eventually fall to the ground? GRAVITY
Inertia— a property of matter that says matter wants to resist any change in motion.
A. If an object is at rest, it wants to STAY AT REST
B. If an object is moving it wants to STAY IN MOTION (MOVING)
C. The more mass an object has, the MORE inertia it has. (Hint—Would you have to work harder
to change the position of a couch or a soccer ball at rest?)
D. Back to the thrown ball. After the player throws the ball, due to inertia, what does the ball
want to keep doing? IT IS IN MOTION Why doesn’t it? Friction slows the ball down and
gravity pulls it down to the ground
In order for an object to change its motion, what must happen?__________________________
CONGRATULATIONS! You just figured out Newton’s 1st law!
Newton’s 1st Law— “An object at rest will STAY AT REST and an object in motion will STAY IN
MOTION at the same speed and in the same direction unless acted on by an UNBALANCED
FORCE.”
E. Some more examples of the 1st Law.
1. The rolling cart and ball.
Notice the ball is in the back of the cart before I push the cart.
When I push the cart, does the ball move? YES
What force caused the ball to start moving? The push from the back of the cart
What happens to the ball when the cart hits the wall? The ball continues to roll forward
Explain in terms of Newton’s 1st law why this happened by answering the questions below.
Why did the ball keep rolling once the cart stopped? The ball was still in motion and it wanted
to stay in motion.
What was the unbalanced force that finally caused the ball to stop moving? The front wall of
the cart.
2. Why do you fall forward when you stub your toe on a chair? Explain in terms (meaning use
the words in the law in your answer) of inertia and Newton’s 1st law.
 You were in motion, when your toe hit the chair, your body
continued to move because it was still in motion. Only your toe/foot
was stopped when you hit the chair!
3. Why do you fly forward when hitting a curb while riding a skateboard or bike? Explain in
terms of inertia and Newton’s 1st law.
 You were in motion, when the skateboards motion was stopped by
the curb, your body still wanted to stay in motion… so…DOWN
you go!
4. Come up with your own example of Newton’s first law! Again- explain using inertia and
Newton’s 1st law.
Name ________________________________
NEWTON’S SECOND LAW-answers
What is acceleration? Acceleration happens whenever something changes its SPEED or DIRECTION.
Sir Isaac Newton did several experiments that looked at force and acceleration. These are his
observations:
A. Applying a larger net force to an object will result in
LARGER acceleration
B. If you apply equal net forces to two objects with
different masses, the one with the smaller mass will
accelerate MORE.
C. If you want 2 objects with different masses to have
the same acceleration, the object with the larger mass
will require A LARGER force.
Based on these observations, Newton came up with a law to describe acceleration.
Newton’s 2nd Law: “The acceleration of an object depends on the FORCE ACTING ON IT
and the MASS OF THE OBJECT
Name ____________________
MORE FROM SIR ISAAC NEWTON-answers
Stand up and firmly push with the palm of your hand on the
EDGE of the table. (DO NOT PUSH THE TABLE FORWARD)
When I say so, stop and look at your hand. What did feel?
PRESSURE FROM THE TABLE
What do you see on your hand? AN INDENTATION/LINE
What put the indentation in your hand? THE TABLE PUSHING YOU
Draw arrows representing the direction of any forces happening in this situation.
Newton’s 3rd Law of Motion --“For every action there is an equal and opposite
reaction”
What is the action in this situation? YOU PUSHING THE TABLE
What is the reaction in this situation? THE TABLE PUSHING YOU
Label them in your picture.
Whenever two objects interact with each other, they exert forces upon each other.
1. Imagine pushing on a (solid) wall (or door ) with a fairly large force, and
assume you don't break through. According to Newton's third law, the wall is
exerting an equal and opposite force back on you.
Explain this in your own words: What is the action? THE ACTION IS YOU
PUSHING ON THE WALL.
What is the reaction? THE REACTION IS THE WALL PUSHING BACK WITH AN
EQUAL FORCE
How do you know the reaction is EQUAL to the action? THE REACTION IS
EQUAL BECAUSE YOU ARE NOT FALLING THROUGH THE WALL AND THE WALL IS NOT FALLING
ON YOU.
Gravity
pulling
person
down
2. When you sit in a chair, your body exerts a downward force on the chair and the chair exerts
an upward force on you! The chair is what keeps you from falling to the ground. It is actually
pushing you upward with a force equal to gravity pulling you down.
What is the action? YOU PUSHING (sitting)ON THE CHAIR
What is the reaction? CHAIR PUSHING UP ON YOU
How do you know the action is equal to the reaction? YOU ARE NOT IN THE GROUND!!
Think of another example like these and explain it in your own words: _____________________
Chair
pushing
up on
person
____________________________________________________________________________________
NEWTONS NOTES-TEACHER DIRECTIONS:
Newton Laws (law #1)
For this activity, I have a cart with a tennis ball (stolen from my children). I
place the ball in the back of the cart and push it hard into the leg of a table.
Students watch the ball roll to the front of the cart after the cart is stopped. WE
discuss that the ball was still in motion so it kept rolling and the cart wall stopped
its motion.
Newton’s Second Law
It is not necessary, but demonstrating the acceleration of the different masses with
different forces.
More from Sir Isaac Newton (law #3)
In the first activity, make sure the students are not pushing the table/desk
forwards, just pushing slightly down on it.