This is the orginal problem.....a.)How much power is needed to push a 95 kg chest at 0.62 m/s along a horizontal floor where the coefficient of friction is 0.78.(ans. 450W)... b.) How much work is done in pushing the chest 11 m? (ans. 7.99x10^3 J)(adsbygoogle = window.adsbygoogle || []).push({});

New question: Answer the previous question when the floor slopes upward at an angle of 5 degrees, and you push parallel to the floor.

Fa=(coefficient of friction)(mg)

P=(F) (v)

W=(F) (delta x)

My attempt is W=(95kg)(9.81m/s^2)(11m)(sin5 +cos5(.78))= 8.81 x10^3 J so solving for power I would use Work/17.74= 496 Watts

.

A different route is P=(.78)(95kg)(9.8m/s^2)(cos5)(.62)=448 W

(solving for t I get 11m/.62m/s=17.74 s) so W=448x17.74 which is 7.96 x10^3 J

-both of these answers are smaller so I do not believe this is true

I am unsure if either of these is right and if both are wrong where have I gone wrong! thank you

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# Homework Help: Finding the power and work needed

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