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Newton’s First Law. Newton’s First Law. An object at rest _____________, And an object in motion ___________________, Until acted on by ______________. Newton’s First Law. An object at rest remains at rest, And an object in motion ___________________, Until acted on by - PowerPoint PPT Presentation
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Newton’s First Law
Newton’s First Law
An object at rest
_____________,
And an object in motion
___________________,
Until acted on by
______________.
Newton’s First Law
An object at rest
remains at rest,
And an object in motion
___________________,
Until acted on by
______________.
Newton’s First Law
An object at rest
remains at rest,
And an object in motion
remains in motion,
Until acted on by
______________.
Newton’s First Law
An object at rest
remains at rest,
And an object in motion
remains in motion,
Until acted on by
an unbalanced force.
Why does the ladder fly off?
The ladder is an object in motion.
An object in motion remains in motion, until acted on by an unbalanced force.
Why does the driver fly out?
The driver is an object in motion.
An object in motion remains in motion until acted on by an unbalanced force.
How does this magic trick work?
• The plates and cups are objects at rest.
• Objects at rest remain at rest until acted on by an unbalanced force.
What do the ladder, driver, and plates have in common?
INERTIA!!!
What is INERTIA?
Inertia: the resistance of an object to change its motion
Inertia is determined by mass.
The larger the object is, the more inertia it has, so the harder it is to change its motion.
Why is it hard to change the motion of a truck?
The truck is massive, so it has a lot of INERTIA.
Which has the most inertia?
Which has the most inertia?
What happens to Napoleon?
Napoleon is an object in motion and he remains in motion until acted on by an unbalanced force, because he
has inertia.
YOUR TURN!!!!
• Get in a group of four.
• You will answer questions about Washers, Test Crash Dummies, Pennies, and Racers.
• You must answer questions in complete sentences, using what you learned about Newton’s First Law and Inertia.
Washers
• Stack up 4 washers• Flick another washer
at the bottom of the pile
1. What happens when you flick the washer at the pile of four?
2. What does the stack of washers have that keeps it from moving?
3. Use Newton’s First Law to explain what happened. “The stack is an object at ________. It remains _________ because there is no _________________.
Test Crash Dummies
4. This test crash dummy remains in motion until it meets the unbalanced force of ______________.
5. When you are in a car and the driver slows down suddenly, what causes the unbalanced force that stops your body? (Assuming you are following the law)
6. Your body keep moving even when the car stops because your body has _________________.
Pennies
• Stack a penny and a card on top of a cup.
• Flick the card out.
7. What happens to the penny when you flick the card out?
8. Why doesn’t the penny fly out with the card? What does it have?
9. An unbalanced force causes the motion of the penny. What is the unbalanced force?
Racers
• 10. Leave the car on your desk. Why doesn’t it move? An object at _______, remains _______, until acted on by ______________.
11. Push the car on your desk. The racer should remain in motion until acted on by an unbalanced force. What is the unbalanced force that slows down the car
Washers
• Stack up 4 washers• Slide another washer
at the bottom of the pile
1. What happens when you slide the washer at the pile of four? The bottom one slides out.
2. What does the stack of washers have that keeps it from moving? Inertia
3. Use Newton’s First Law to explain what happened. “The stack is an object at rest. It remains at rest, because there is no unbalanced force.
Test Crash Dummies
4. This test crash dummy remains in motion until it meets the unbalanced force from the air bag.
5. When you are in a car and the driver slows down suddenly, what stops your body? Seatbelt.
6. Your body keep moving even when the car stops because your body has inertia.
Pennies
• Stack a penny and a card on top of a cup.
• Flick the card out.
7. What happens to the penny when you flick the card out? The penny falls into the cup.
8. Why doesn’t the penny fly out with the card? It has inertia.
9. An unbalanced force causes the motion of the penny. What is the unbalanced force? Gravity pulls the penny down.
Racers
•
10. Leave the racer on your desk. Why doesn’t it move? An object at rest, remains at rest, until acted on by an unbalanced force.
11. Push the racer on your desk. What is the unbalanced force that slows down the racer? Friction is the force that slows things down.
