Question

when you brake a car at a stop sign, what force provides the impulse to stop the car?
drwls
INTERNALLY, a torque applied to wheels by brake pads and cylinders causes the wheels to turn more slowly, and this results in an EXTERNAL increased backwards friction force applied by the road to the tires. The frictional heating as kinetic energy is lost takes place in the brakes (unless the car is a hybrid), not on the road surface.