A passenger car employs a hydraulic brake system that sends the pressure created in the master cylinder to four wheel-caliper pistons through brake fluid confined in rigid lines.
(i) State Pascal’s principle as applied to fluids in equilibrium.
(ii) Giving suitable reasoning, explain why the pressure produced by the driver’s foot in the master cylinder is transmitted to every point in the brake lines without any reduction, even though the pipes may bend and rise above the master cylinder level.
(iii) The pistons in the front wheel calipers have a diameter of 40 mm each, whereas those in the rear wheel calipers have a diameter of 30 mm each. When the same pressure acts on all pistons, compare qualitatively the magnitudes of the braking forces on the front and rear wheels. Explain why an automobile designer might deliberately choose different piston sizes for the front and rear brakes.