What causes the radio and all inside lights to shut off for a split second and the RPM and mph hand to go down when pushing on the brakes in a 1997 Pontiac Firebird?
Pinched wire under the dash near the brake pedal assembly.
If only external force can change the velocity of a body how can the internal force of the brakes bring a car to rest?
It is not the force of the brakes that is stopping the car but rather external force of friction between tires and the road. Notice that no matter what the force at the brakes is, the car won't stop if there is no friction there(ie. the road is slippery). This is an excellent question. Consider the NASA space shuttle. It has brakes, yet the brakes work only on the ground - only while the shuttle…