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Unit 1: Mechanics Page 26
hypothesis. On a scale from 1 to 5 The race car doesn’t have to worry
(or however many shoes you’re about rain or wetness so it wants
using) rate the shoes you picked. 1 every single bit of the tire to be
is low friction and 5 would be high touching the surface of the track.
friction. Write the hypothesis next That way, there is as much friction
to a description of the shoes on a as possible between the tire and
piece of paper. The greater the the track. The tire on your car has
friction the higher the ramp has to treads to cut through mud and
be lifted. Test all of the shoes. water to get to the nice firm road
underneath. The treads actually
7. Analyze the shoes. Do the shoes give you less friction on a flat dry
with the most friction show any road!
similarities? Are the bottoms made
out of the same type of material? Some of you might have used a
What about the shoes with very skateboard shoe for your
little friction? experiment. Notice, that the
skateboard shoe has quite a flat
Any surprises with which shoe had bottom compared to most other
the most or least friction? Compare shoes. This is because a
the shoe with the most friction and skateboarder wants as much of his
the shoe with the least friction. Do or her shoe to touch the board at
you notice anything? Usually, the all times.
shoe that has the most friction has
more shoe surface touching the Experiment: Stick and Slip
board then most of the other
shoes. Friction is everywhere! Imagine
what the world would be like
Also, often the shoe with the least without friction! Everything you do,
friction, has the least amount of from catching baseballs to eating
shoe touching the board. Since hamburgers, to putting on shoes,
friction is all about two things friction is a part of it. If you take a
rubbing together, the more surface quick look at friction, it is quite a
that’s rubbing, the more friction simple concept of two things
you get. A tire on you car should rubbing together.
have treads but a race car tire will
be absolutely flat with no treads at However, when you take a closer
all. Why? look at it, it’s really quite complex.
What kind of surfaces are rubbing
together? How much of the
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