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# work help?

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A girl places a stick at an angle of 60.0° against a flat rock on a frozen pond. She pushes at an angle and moves the rock horizontally for 2.00 m across the pond at a velocity of 4.00 m/s and a power of 160.0 W. What force did she apply to the stick? How much work did she do?

Feb 11, 2020

#1
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Power = Force * velocity

force parallel to movement would be   F cos 60

Power = F cos 60 * 4 m/s

160 W  = F cos 60 * 4 m/s

160   kg-m2/s3   = ( F cos 60) kg-m/s2      * 4 m/s     Solve for F  (which will be in Newtons      A newton is  kg-m/s2)

Then use the "F" found above:

Work = F * d   =    F  *  2 m

Feb 11, 2020
edited by ElectricPavlov  Feb 11, 2020

#1
+2

Power = Force * velocity

force parallel to movement would be   F cos 60

Power = F cos 60 * 4 m/s

160 W  = F cos 60 * 4 m/s

160   kg-m2/s3   = ( F cos 60) kg-m/s2      * 4 m/s     Solve for F  (which will be in Newtons      A newton is  kg-m/s2)

Then use the "F" found above:

Work = F * d   =    F  *  2 m

ElectricPavlov Feb 11, 2020
edited by ElectricPavlov  Feb 11, 2020