Answer:
force on brake shoes is 10 N
Step-by-step explanation:
for the master cylinder;
force applied = 140 N
diameter = 14d
for brake cylinder;
force applied on the brake shoe by the brake cylinder f = ?
diameter = d
The pressure will be transmitted undiminished from the master cylinder to the brake cylinder according to pascals pressure law.
pressure = force/area
but cross sectional area is proportional to diameter of the cylinder
therefore
the diameters will cancel out, and we're left with
force on brake shoes = 10 N