2. Newtons 3rd LawEvery action has an equal andopposite
reaction, unless acted on by an unbalanced force. 3. Friction
Friction a resistance betweentwo objects To find friction, you take
themass of the object and multiplyit by the frictional coefficient.
4. LABFriction 5. Objective Demonstrate static and kinetic
friction, and see how friction changes when the surface is
different 6. Materials Rubber band Shoe with rubber bottom Ruler 7.
Procedure Weigh shoe Cut rubber band and tie one end to the shoe
Set shoe on asphalt and start pulling on theother end of the rubber
band until the shoestarts to move Use ruler to measure how far the
rubber bandstretches before the shoe moves Once its moving measure
how far the rubberband is stretched Compare measurements Repeat
steps 3-6 on concrete instead of asphalt 8. Static and Kinetic
Friction After comparing measurements, we foundthat the rubber band
stretches fartherbefore the shoe starts to move. This isbecause it
has to overcome static force forit to move. Once it was moving, the
stretch of therubber band wasnt as much, because thenit was just
being influenced by kineticfriction. 9. Calculating Friction To
find the value of the frictional force, youmultiply the weight of
the object by the frictionalcoefficient. For the first trial, we
used the rubber bottom of ashoe on asphalt. That coefficient is
0.9, so wemultiply the shoes weight by 0.9 For the second trial, we
used the rubber bottomon concrete, and that coefficient is 0.7.
Then wemultiply the weight by 0.7 10. Friction and Newtons 3 rd
LawFriction is related to Newtons 3rd law(every action has an equal
and opposite reaction). When you try topush or pull an object, a
frictionalforce is always acting against that motion, whether its
in the air or onanother surface.
