The Physics of a Seesaw


        Lifting up a case of water can be a little difficult, but could you lift another person??  The more mass something has, the harder gravity pulls down on it.  But people have learned to 'outsmart' the force of gravity by using a simple machine such as a lever, which is a key concept in the seesaw.

http://www.fmalive.com/_downloads/playground_physics.pdf
Pivot point is the triangle


A seesaw is a great example of a lever.  The fulcrum/pivot point is the part of the lever that does not move, its in the middle.  The resistance, or the downwards force, is the weight of the person you are trying to lift is at one end.  The work, force applied to the lever, is the person sitting on the other end of the seesaw.


                                                http://www.google.com/imgres?imgurl=http://www.amphi.com/schools/images/F7A8CC57A4CE45F08C21BD457B5D1BDB.gif&imgrefurl=http://www.amphi.com/schools/holaway/specialists.html&usg=__hky-gVP6MNZvxh9D7UH2YctLX80=&h=178&w=238&sz=12&hl=en&start=9&zoom=1&tbnid=4JShP0NvtcG2BM:&tbnh=82&tbnw=109&ei=RGauTdvsCO_ciALeu9WQDA&prev=/search%3Fq%3Dcartoon%2Bsee%2Bsaw%26um%3D1%26hl%3Den%26client%3Dfirefox-a%26sa%3DN%26rls%3Dorg.mozilla:en-US:official%26biw%3D1366%26bih%3D556%26tbm%3Disch&um=1&itbs=1                            

The force that is applied by pushing down/pushing up on one end of the seesaw can substitue for the mass on the other end.  The longer the lever, the less force one needs to lift a heavy object.

"The mechanical advantage of using a long lever to lift a heavy weight is
apparent: much less force is need to lift a heavy object with a lever if the distance
from the pivot point is large compared to the distance of the heavy object from the
pivot point." --See Saw Physics Lesson



http://www.google.com/imgres?imgurl=http://www.world-builders.org/lessons/less/les1/mathpgs/balance_1.gif&imgrefurl=http://www.world-builders.org/lessons/less/les1/binary_stars_1.html&usg=__O3PlJ0clgJ6MDiCjYzQlCaMenE4=&h=261&w=498&sz=7&hl=en&start=0&zoom=1&tbnid=v-BMilch8rJX-M:&tbnh=96&tbnw=183&ei=1GauTYLTL4jjiAK__pCADA&prev=/search%3Fq%3Dbalanced%2Bseesaw%26um%3D1%26hl%3Den%26client%3Dfirefox-a%26sa%3DX%26rls%3Dorg.mozilla:en-US:official%26biw%3D1366%26bih%3D585%26tbm%3Disch&um=1&itbs=1&iact=hc&vpx=297&vpy=300&dur=7&hovh=162&hovw=310&tx=186&ty=92&oei=1GauTYLTL4jjiAK__pCADA&page=1&ndsp=18&ved=1t:429,r:13,s:0



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