what is friction ( contact force ) force that acts when two objects rub (contact) each other...
TRANSCRIPT
What is Friction ( contact force )Force that acts when two objects rub (contact)
each otherFriction comes from solid, air or water
http://phet.colorado.edu/sims/friction/friction_en.html ( Let us visit this website)
How does Friction affects motion?
Friction opposes movement
How does Friction affects motion?
Slows down
How does Friction affects motion?
Getting moving
How does Friction affects motion?
Getting moving
How does Friction affects motion?
Grip or stop
Factors affecting friction ( surface)http://www.bbc.co.uk/schools/scienceclips/ages/8_9/friction.shtml ( visit this website)
Smooth surface Rough surface
Lesser bump and hollows means lesser
frictioncan move the object continuously with little
force.
More bump and hollows means more friction
Can move the object slowly with greater force
Smooth surfaceThe smoother the surface the faster the object glides with little force
Rough surfaceObjects will move slowly with greater force on the rough surface.
Factors affecting frictionAir Resistance Example:Is the force that provide a backward
forceSize and shape are the
factors that affect air resistance. ( the
bigger the size and shape the more is the
air resistance)
http://www.youtube.com/watch?v=oTMLXBeQ40E
http://www.youtube.com/watch?NR=1&v=ur40O6nQHsw
Friction: Good and BadGood BadHold objectsStops objectAble to play ,run ,walk
etcGives energy
Shoes, slippers , tires and anything that are used for moving are worn out.
Machine become less efficient
Reduce speed Cause accidents Cause sparks
Ways of reducing frictionApplying wax or polishingUse rotating objectsStreamliningNew design shoes for the athletes