Friction

Force the opposes motion between 2 surfaces

• force
• Newton
• friction
• net force

What are the 2 types of friction discussed in the book?

• Static and Dynamic Friction
• Kinetic and Static Friction
• Kinetic and Dynamic Friction
• Dynamic and Moving Friction

Tags

NGSS.HS-PS2-1

What are 2 factors that determine the amount of friction between 2 objects?

• Force and roughness between surfaces
• hills and valleys and how smooth or rough the surface is
• Amount of force and amount of surface the comes in contact
• The force and the weight exerted on the surfaces

Which of the following is opposed by kinetic friction?

• A truck being pushed but not moving
• A box being pushed but not moving
• A box being pushed and sliding across the floor
• A wagon being pulled but not moving

Which of the following is an example of friction that is helpful?

• Brakes used on a bike
• Tires from a car on the road
• Tread on the bottom of your shoes
• All are examples that are helpful

Which of the following is an example of friction that is harmful?

• Pencil marking on paper
• Engine parts wearing out
• sand placed on ice in the winter
• Using an eraser to erase marks

How can friction be reduced?

• reduce the force acting between the 2 surfaces
• reduce the roughness of the 2 surfaces coming in contact
• use wax, grease or oil
• all of the above are ways of reducing friction

Tags

NGSS.HS-PS2-3

Which would NOT be a way of reducing friction?

• making the surfaces smoother
• using lubricants such as waxes, oils, or grease
• changing from sliding friction to rolling friction using ball bearings
• Using kitty litter on snow and ice to help your car gain traction

What type of friction is not moving?

• static
• dynamic
• kinetic
• rolling

Tags

NGSS.MS-PS2-2

Which of the following is an example of rolling kinetic friction?

• box sliding across the floor
• bike rolling along the road
• car skidding to a stop
• soccer player making a slide tackle