normal force=F*cos25
friction force= .51*F*cos25
downward force= mg-F*sin25
setting downward force= friction force
mg-41*sin25=.51*41*cos25
now solve for mass m.
A small box is held in place against a rough vertical wall by someone pushing on it with a force directed upward at 25o above the horizontal. The coefficients of static friction and kinetic friction between the box and wall are 0.21 and 0.51, respectively. The box slides down unless the applied force has magnitude 43-N. What is the mass (in kg) of the box?
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