1. Forces & Motion

2. Motion A change in the position of an object
Caused by force (a push or pull)

3. Force Anything that is pushing or pulling on an object
Measured in units called Newtons (N)
Measured with a spring scale
Forces act in pairs

4. Types of Force:
Gravity- pulls objects towards each other and pulls toward the center of Earth
Friction- when two surfaces rub against each other
opposes motion
Increasing friction will slow an object down
Decreasing friction allows an object to move more freely
Magnetism – iron and steel are attracted to magnets
opposite poles of a magnet attract and like poles repel
Electricity – these forces are produced when an object gains or looses electrons.
Charged objects can exert a push or pull force on each other.
Study Jams - Force Video

5. Mass and Weight Mass is the amount of stuff (matter) in an object.
The mass of an object will remain the same anywhere in the universe.
Mass is measured in grams or kilograms.
Weight is the mass (kg) of an object multiplied by the acceleration of gravity (9.8 m/s2).
The weight of an object depends on the gravitational pull of the location in the universe.
The gravitational pull on the Moon is only 1/6 of Earth’s gravitational pull.
Weight is measured in newtons (N).

6. Newton’s 1st Law of Motion
Inertia
Inertia is the tendency of an object to resist change to its state of motion.
Newton’s 1st Law of Motion
An object at rest will remain at rest until acted upon by another force.
An object in motion will remain in motion until acted upon by another force.

7. Balanced Forces
When all the forces acting on an object are equal (net force is zero)
Balanced forces do not cause a change in motion.

8. How Can Balanced Forces Affect Objects?
Cause an object at rest to stay at rest or an object in motion to stay in motion (inertia)
Cause an object moving at a constant speed to continue at a constant speed
In your notes, describe an example of a balanced force affecting an object.
Study Jams - 1st Law of Motion Video

9. Newton’s Second Law of Motion
The greater the force on an object, the greater the acceleration on an object. The smaller the mass of an object, the greater the acceleration will be in comparison to an object with a larger mass.
Force= mass x acceleration

10. Unbalanced Forces
When all the forces acting on an object are not equal
The forces can be in the same direction or in opposite directions.
Unbalanced forces cause a change in motion.

11. How Can Unbalanced Forces Affect Objects?
Acceleration is caused by unbalanced forces:
slow down
speed up
stop
start
change direction
In your notes, describe an example of an unbalanced force affecting an object.
Study Jams 2nd Law of Motion Video

12. Newton’s 3rd Law of Motion
For every action or force, there is an equal and opposite reaction or force.
Study Jams 3rd Law of Motion Video

13. Work The use of force to move an object through a distance.
Take your highlighter and circle this word on your vocabulary list.
Did you do it? If you did, you did work! You moved your hand and the highlighter a distance!
That’s just about all the work I want to do today, so write a different example of work being done on a sticky note and list what force is doing the work. Stick it on the board before you leave!