1. Friction
When two surfaces rub together, the irregularities of one surface
The force that one surface exerts on another
Friction acts in a direction

2. Friction Without friction, the object would continue to move at
The strength of the force of friction depends on two factors:

3. Friction
When two surfaces rub together, the irregularities of one surface
get caught on those of the other surface.
The force that one surface exerts on another
when the two rub against each other is called Friction.
Friction acts in a direction
opposite to the object’s direction of motion.

4. Friction Without friction, the object would continue to move at
constant speed.
The strength of the force of friction depends on two factors:
the type of surfaces involved and
how hard the surfaces push together.

5. Different Types of Friction
__________ Friction – when solid surfaces slide over each other. ( _____ Friction)
__________ Friction – when an object rolls over a surface. (_____ Friction)
_______ Friction – the friction that occurs when an object moves through a liquid or a gas. (______ Friction)

6. Different Types of Friction
A liquid or gas is commonly used to
Lubricants change _______________ friction to ______________ friction.

7. Different Types of Friction
Sliding
__________ Friction – when solid surfaces slide over each other. ( _____ Friction)
Most
Rolling
__________ Friction – when an object rolls over a surface. (________ Friction)
Some
Fluid
_______ Friction – the friction that occurs when an object moves through a liquid or a gas. (______ Friction)
Least

8. Different Types of Friction
A liquid or gas is commonly used to
reduce friction; they are known as- Lubricants.
sliding
Lubricants change ___________ friction to __________ friction.
liquid