Wheels, Rollers & Pulley

How would you overcome friction? 

• add a smooth surface, like an ice surface 
• add a rough surface like sand paper
• add less force to move the object

What is friction? 

• when an object moves very quickly 
• the action of one object rubbing against another surface
• when an object  can not move at all 

Which object uses a roller to reduce the force of friction? 

• ice skates
• car
• rolling pin

Where is the best location for axles on a wheel to make the object move smoothly?

• no where on the wheel 
• on the outer edge of the wheel
• in the middle of the wheel 

What kind of pulley is this? 

• fixed pulley
• block and tackle 
• movable pulley

What kind of pulley system is this? 

• block and tackle pulley
• movable pulley
• fixed pulley

What kind of pulley sytem is this?

• fixed pulley
• block and tackle pulley
• movable pulley