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F=??. Angle=45 deg. Warm Up Day 35(55). A 2.5 kg physics book is held against a wall by a student who applies a force at a 45 deg angle. What minimum force must he use to hold it still against the wall if the coefficient of static friction is 0.35?. Solution. Sum forces in x and y directions
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F=?? Angle=45 deg Warm Up Day 35(55) A 2.5 kg physics book is held against a wall by a student who applies a force at a 45 deg angle. What minimum force must he use to hold it still against the wall if the coefficient of static friction is 0.35?
Solution • Sum forces in x and y directions • Fx=Fcos45-N • Fy=Fsin45-mg+Friction • Friction<= msN, use equal for min F Fsin45=mg-friction= Fsin45=mg- msFcos45) F=mg/(sin45+ mscos45)= F=25.7N