ข้อดี
1.friction make our shoes grip the ground so that can we walk without slipping
2.friction enable us to hold things
3.friction enable us to drive our car or ride our bicycles
4.friction enable thing to rest on the table or on the ground and lean against the wall
5.friction can produce sound
ข้อเสีย
1.friction slows down all moving objects
2.friction make object hard to moving
3.friction can make noise
4.shoes and tyres wear out because of friction went they rub against the road
5.friction not only wear out machine parts but also produce heat that can damage sensitive parts in the machine
‘’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’
Scalars are quantities that are fully described by a magnitude or numerical value alone.
Scalars is no direction for ex. Distance speed 5m.
Vector are quantities that are fully described by both a magnitude and is direction.
Vector have direction for it ex. Displacement velocity 5m/sec west
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Growth expansion or recovery posperity peak or boom slow down contraction or recession lowest point