Why does it slide forward when the driver applies the brakes?

When a driver applies the brakes, the vehicle experiences deceleration due to the friction between the brake pads and the brake rotors. This rapid slowing down shifts the weight of the vehicle forward, causing any unsecured objects or passengers to slide in the same direction. Additionally, the inertia of these objects causes them to continue moving forward until they are stopped by a seatbelt or other restraint.