1.3 Friction & 1.4 Gravity (Final)

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

A pencil falls off of a desk. What moves the pencil toward the floor? 

• mass
• friction
• gravity
• speed

Which model has greater gravitational attraction (if any)

• Both Model A and Model B (same gravity)

• Model B
• Model A

People often try and reduce friction by ....................the bottoms of their skis to reduce friction and make them go faster.

• waxing

• lubricating

• using ball-bearings at

Which type of material would cause the greatest amount of friction?

• sheets of wax paper

• smooth kitchen tile

• shiny wood table top

• coarse sandpaper

If a person steps in water spilled on the ground, and slips; they are slipping because there is too little of what force?

• friction

• motion

• lifting

• gravity

As mass increases, what happens to gravitational force?

• increases
• decreases
• stays the same
• i don't know

Which of the following will not change in different gravitational fields?

• wieght
• force
• mass
• pounds

People often try and reduce friction by putting oil on the axles of their bicycles to reduce friction which is called..................................

• waxing.

• lubrication.

• ball-bearings .

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

• Brakes used on a bike

• Tyres from a car on the road

• Bike chain rubbing against the gears

• A person moving down a slide.