The exact formula for kinetic energy is , where is the mass of an object and is its speed. This was useful to Mark because braking from 100 mph was within the range of familiar driving experience. The efficiency of the braking process, dissipation, will depend on details of the friction interaction between the brake pads and disks. That interaction is likely to vary with temperature. Most brake pads are formulated to grip harder when hot, but only up to a point.
Brake fade occurs when the pads and rotors are overheated.
If you continue braking, heating the system even more, the brake fluid will eventually boil and there will be no braking at all. Brake fluid has the function of transmitting the pressure of your foot on the pedal to the brake pads by hydrostatics. If the fluid boils, then the pressure of your foot on the pedal goes into crushing little bubbles of gaseous brake fluid in the brake lines rather than into crushing the pads against the disks. Hence, no brakes. We now arrive at the second way of looking at this problem.