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Urmi Roy
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Homework Statement
What horizontal force P must be applied to the weightless wedges to start them under the 450kg block,(the angle of friction for all contact surfaces is 10 deg.).
Homework Equations
The Attempt at a Solution
I tried out the sum in the method that came to my mind first...this is illustrated in the diagrams...
(coeff. of friction at all suraces (mu)=tan10=,176)
the weight of the 450kg block on either wedge is 225kg(each share the weight equally)...but the friction along the top surface of the wedge(in green) is calcuated by mu*(component of the block's weight perpendicular to the wedge's upper surface i.e 225gcos15,where g=acc. due to gravity).
Also,to calculate the friction at the base,we calculate the net downward force...
N-225g+fsin15=0
=> N=225g-fsin15
and F(in pink)= mu*N
Thus,we can easily calculate the net horizontal force P to overcome these two frictional forces...the problem is,my answer does not match the answer in the book(1417.31N)
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