Answer:
The test dummy will continue forward until it makes contact with another object.
Step-by-step explanation:
When a car brakes abruptly the body of the test dummy is thrown forward, the law of inertia comes into play. Therefore, the use of the seat belt is essential to ensure the integrity of the passengers.
The test dummy is at rest relative to the car and in relation to the ground, the speed of the body of that doll is zero. A collision of the car with some object pushes the puppet forward, causing it to vary from zero speed to a nonzero speed.
If a test dummy is buckled, but another test dummy in the back seat of the car is without the belt, at the time of braking, it will be thrown in relation to the car at the speed that the car had instantly before the moment of braking. That is, test dummy will continue to advance until it contacts another object.