Forces… change the motion of objects in predictable ways.

Forces change motion Now you will learn: What a force is How unbalanced forces change motion Newton’s first law

Now you will learn:

What a force is

How unbalanced forces change motion

Newton’s first law

Force A force is a push or a pull

A force is a push or a pull

Types of Forces (3) 1. Contact force When one object pushes or pulls by touching another object, the first object is applying a contact force to the second

1. Contact force

When one object pushes or pulls by touching another object, the first object is applying a contact force to the second

Types of Forces 2. Gravity The force of attraction between two masses

2. Gravity

The force of attraction between two masses

Types of Forces 3. Friction A force that resists motion

3. Friction

A force that resists motion

Net Force Overall force acting on an object - A net force of 0 is balanced - Motion does not change

Overall force acting on an object

- A net force of 0 is balanced

- Motion does not change

Net Force Unbalanced forces - Change motion

Unbalanced forces

- Change motion

Newton’s First Law Things keep doing what they’re doing Objects at rest remain at rest, and objects in motion remain in motion with the same velocity, unless acted upon by an unbalanced force

Things keep doing what they’re doing

Objects at rest remain at rest, and objects in motion remain in motion with the same velocity, unless acted upon by an unbalanced force

Inertia Is it easier to push or pull a full shopping cart or an empty one? Inertia – resistance of an object to change the direction or speed of its motion

Is it easier to push or pull a full shopping cart or an empty one?

Summary Force- a push or a pull Net force- balanced and unbalanced 3 types of forces Contact, Gravity, Friction Newton’s first law Inertia

Force- a push or a pull

Net force- balanced and unbalanced

3 types of forces

Contact, Gravity, Friction

Newton’s first law

Inertia