1. The problem statement, all variables and given/known data Write an expression for the force applied to the brake caliper in the braking system(hydraulic) of a bicycle. F= force applied to the brake lever a = distance between F and the pivot point of the brake lever. b= distance between pivot point and lever piston. d1= diameter of the piston on the brake handle d2 = diameter of piston on the brake caliper. (PS English is not my mother tongue, so I might have used the wrong words for the different parts of the brake system. I do hope it's possible to understand what I mean.) 2. Relevant equations Pascal's law Force * arm 3. The attempt at a solution Right away I'm thinking Pascal's law. My first thought is to write pressure, p, = F1/d1 = F2/d2. I'm a bit unsure about where to incorporate distances a and b. I'm tempted to use force*arm and write the whole expression as p=(F1*a)/d1 = (F2*b)/d2, but is this correct...?