Posted by michelle on .
A hydraulic brake system is shown. The
area of the piston in the master cylinder is 6.32 cm^2, and the area of the piston in the brake cylinder is 1.83 cm^2. The coeﬃcient of kinetic friction between the brake shoe and the wheel drum is 0.443.
How large is the frictional force between the brake shoe and the wheel drum when a force of 49 N is exerted on the pedal? Answer in units of N.

physics 
Elena,
Pascal’s principle F1/A1=F2/A2.
F(bc)={A(bc)/A(mc)}•F(pedal) =
=(1.83/6.32) •49 =14.2 N
This is the normal force exerted on the brake shoe.
The frictional force is
F(fr) =μ F(bc)=0.442•14.2 =6.3 N 
physics 
michelle,
Wow thank you so much! This problem has been bothering me for a week now