This is entirely dependent on how your vehicle is designed. Pulling the electronic parking brake in my car (Audi S4) at a decent speed applies maximum braking effort to all 4 wheels simultaneously. It'll practically pop your eyeballs out.

Interesting. Although if that brake is electronic you can't really use it as backup in case something goes wrong with the car's computer systems.

Define "decent." I lost all hydraulic brakes on my 87 Toyota pickup due to a hole in a brake line and I had to drive it to the repair shop using only the cable-operated handbrake. Granted, I didn't go on the interstate, but at some point I was still doing 35-40mph.

Having a stick shift definitely helped, though.