A hydraulic brake system is shown. Thearea of the piston in the master cylinder is6.39 cm2, and the area of the piston in thebrake cylinder is 1.75 cm2. The coefficient ofkinetic friction between the brake shoe andthe wheel drum is 0.484. How large is the frictional force between thebrake shoe and the wheel drum when a forceof 46 N is exerted on the pedal?If you can explain this as well it would be helpful. Thanks
The pressure in the hydraulic system is constant. So, when a force F is applied to the piston in the Master Cylinder (not the same as the pedal due to mechanical advantage and vacuum assistance in the braking system), then it produces a pressure P of F divided by the area of the piston: 46/6.39 N/cm2. When this pressure is applied to the cylinder piston, it produces a force f of P times the area of the piston: (46/6.39)*1.75 N. When this is applied to the brake drum, f is multiplied by the coefficient of friction (0.484) so the final force on drum is: (46/6.39)*1.75*0.484 N
