Which of these reduces fnction? a car brakesbtire treadcball bearingsdsandpaper

Ball bearings are used to reduce friction. (C)

Car brakes, tire tread, and sandpaper are used to INCREASE friction.  There are many situations in which friction is a GOOD thing and we WANT it.

a charge 3q is at the origin, and a charge −2q is on the positive x axis at x=a. part a where on the x-axis would you place a third charge so it would experience no net electric force? enter an expression for the exact answer, which will involve a square-root sign. (do not enter an approximate decimal answer.)

the answer to this is proletariats.

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