Typically, a knocking noise when to use your brakes in the car is caused by your brakes wearing down. This means you need to get them checked out and repaired.
When there are any issues with your brakes it is best to take your car in to a certified mechanic. Brakes can knock for several reasons, including the calipers, brake pads, and bearings.
Most common cause would be a loose brake caliper mounting bolts.
loose rear caliper or drum brakes, could be loose hardware or on disc brakes, possible warped rotor
I would advise bringing your car to a mechanic as quickly as possible. Your brakes could fail. This puts you at a high risk for injury or even death.
The friction caused by the brakes causes the car to decelerate. This negative acceleration, in turn, causes a force to be applied to all those in the car. This is the lurch you feel.
You forgot to let your wife in
it could be your valves or your engine
It's really hard to understand what you're asking here."What causes a knocking sound when your car drops into a hole while driving?"If that's your question, I imagine that it would be the sound of your car dropping into a hole.
Weight transfer. When a car brakes, its weight moves forward and causes the front brakes to do the majority of the work in stopping the car.
Gearbox oil needs changing.
It's the spirit of the car knocking on the side saying "HELLO??? TAKE ME TO A MECHANIC!"