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Q & A: Friction our 'friend'?

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Most recent answer: 10/22/2007
Q:
Why is friction our friend?
- Upreet (age 14 )
Old Bridge, NJ
A:
Assigning human qualities to forces, like friendliness, isn't something physicists do. In school, teachers sometimes asked questions like that, but we didn't always like it. Any physical phenomenon is convenient sometimes and inconvenient other times.

Anyway, friction is needed in countless ways. Among these are the friction between your shoes and the ground, which allows the ground to exert sideways forces on you. Thatís why you can walk. Likewise, cars wouldnít be of much use if there were no friction between the tires and the ground, since then they couldnít accelerate.

On the other hand, the friction between parts inside an engine robs it of some power.

your friend, Mike W.

(published on 10/22/2007)

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