Friction Flashcards
1
Q
Friction - Def
A
Friction is the force acting parallel between two contacting surfaces that tend to rub ot slide past each other
2
Q
Does friction require movement?
A
No!
3
Q
Friction is…
A
- FUN!
- N is related to the reaction force and is always perpendicular to the surface. Anytime N becomes less, friction becomes less. Ex: Driving down a hill you accelerate due to lack of friction
4
Q
A
Friction magnitude is VARIABLE
- Until sliding occurs, friction magnitude = motive force “limiting friction”
- Once sliding occurs, friction magnitude decreases, “sliding friciton”
5
Q
Factors affecting Friction
A
- Materials of contacting surfaces
- Soles of shoes, cartilage vs fibro cartilage, crutch tips and floor
- Cleats vs Tennis shoes on turf vs on tile
6
Q
Changing Friction down a hill
A
N is force that is equal to the parallel force. As the hill gets steeper the N gets smaller therefore less overall force. Leads to you speeding up in a car.
7
Q
Why is cartilage irreplaceable?
A
Nothing manmade that is as slippery. Joint replacements must be replaced after 10-20 years due to friction wearing it out
