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harpua09
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Homework Statement
A worker pushed a 26kg block 13m across a level floor at a constant speed, with a force directed 40 degrees below the horizontal. If the coefficient of kinetic friction between the block and floor is 0.40, what were a.) the work done by the workers force? and b.) the increase in thermal energy of the block floor system?
Homework Equations
F(friction) = coefficient of friction x normal force
E(thermal) = F(friction) x d
The Attempt at a Solution
I am stuck with being able to calculate the normal force on the block without knowing the magnitude of the applied force. I Know that that F(normal) = F(gravity) *m*a*cos(o)
I think that
F(friction) = -F(applied) ,
but i am not sure what to do with this. Does something cancel?
Thanks in advance