Quiz 1: Friction Flashcards
Friction and motion occur at the same time.
True
Graphite crystals can be used as a lubricant.
True
Kinetic friction occurs when an object is pulled over a surface.
True
Friction should always be reduced, if possible.
False
The shape that has the least friction in air is _____
streamlined
To reduce friction in a roller skate wheel, we could use _____
A lubricant
Ballbearings
Polished surfaces
A box weighing 18 newtons requires a force of 6 newtons to drag it across a floor at constant speed. The coefficient of kinetic friction is _____
0.33
The box weighing 18 newtons is coated with Teflon® and now requires a force of 3 newtons to drag it across a floor at constant speed. The coefficient of friction is _____
0.2
Some of the simplest machines are _____
Tools
All machines which involve motion convert energy from one form to another.
True
The force which always accompanies the moving of parts is _____
friction
Friction always produces _____ which is unusable _____.
Heat
Energy
Friction between sliding surfaces is dependent upon the _____ force.
normal
The ratio between the force of friction and the normal force is the _____ of friction.
coefficient
The force required to slide an object is equal to _____
friction
