1. Chapter 2 – Lesson 2

2. Newton’s 1st Law
An object at rest tends to stay at rest and an object in motion tends to stay in motion unless acted upon by an unbalanced force.

3. Part 1: An Object at Rest Identify an object at rest
Ex: chair on the floor, a plane on a runway
These objects will not start moving until a is exerted on them.
Ex:
push or pull
You tend to fall backward when your school bus starts to move.

4. Part 2: An Object in Motion
An object moving at a certain velocity will continue to move at the same speed and in the same direction unless some acts on it.
cfm
forever
unbalanced force
Ex: Riding in your car. When your mother or father comes to a stop then you would continue to move, however your seatbelt stops you.

5. Balanced Force Equal forces in opposite
directions produce no motion or
moving at a constant speed in
one direction

6. Unbalanced Force Unequal opposing forces produce an unbalanced force
causing motion or a change in
Direction.

7. If objects in motion tend to stay in motion, why don’t moving objects keep moving forever?
Things don’t keep moving forever because there’s almost always an acting upon them.
A book sliding across a table slows down and stops because of the force of
If you throw a ball upwards it will eventually slow down and fall because of the force of
unbalanced force
friction
gravity

8. The tendency of an object to resist a change in its motion
Inertia
The tendency of an object to resist a change in its motion
Inertia can be described as the tendency of an object to keep doing whatever’s it’s doing.

9. Inertia Inertia is the reason objects at rest and objects in motion
remain at rest
remain in motion
Inertia is the reason you slide toward the side of a car when the driver makes a sharp turn.

10. Which vehicle has more inertia?
MASS and INERTIA
The more an object has, the more the object has.
Therefore an object with a small mass will have a inertia
And an object with a large mass will have a inertia.
Bigger objects are to start & stop
MASS
INERTIA
SMALL
LARGE
HARDER
Which vehicle has more inertia?

11. Inertia

12. The truck is in motion. What is the force that causes it to stop?
The car is at rest. What is the force that causes it to move?
The push of the stopped car.
The push of the truck.

13. Group Work!
In your group take 3 MINUTES to come up with an example of Newton’s 1st Law in everyday life. Be ready to explain using the proper vocabulary.

14. Assess Your Knowledge
If gravity between the Sun and Earth suddenly vanished how would Earth move?
Answer: In a straight path

15. To say that 1kg of matter weighs 10 N is to say that 1kg of matter
Will weigh 10N everywhere
Has less volume than 10kg of matter
Has more inertia than 10kg of matter
Is attracted to Earth with 10N of force
Answer: D

16. If the net force on an object is zero then the object has
Balanced forces
Action forces
Reaction forces
Unbalanced forces
Answer: A

17. The greater the mass of an object,
The easier the object starts moving
The more space the object takes up
The greater its inertia
The more balanced it is
Answer: C