Final answer:
When the accelerator is released to stop the vehicle's forward propulsion, the vehicle slows down gradually (Option 1).
Step-by-step explanation:
When the accelerator is released, the vehicle's engine reduces or stops supplying power to the wheelS (Option 1). The deceleration is gradual, and the vehicle slows down due to various factors like air resistance, rolling resistance, and the mechanical resistance of the vehicle components.
The slowing down process is governed by the principles of physics, particularly Newton's first law of motion, which states that an object in motion tends to stay in motion unless acted upon by an external force. In this case, the external force is the combination of resistive forces mentioned earlier.
The vehicle doesn't come to a sudden stop unless the brakes are applied. If the brakes are engaged, a different set of forces come into play, and the vehicle can come to a stop more quickly.
In summary, releasing the accelerator initiates a gradual reduction in speed due to the natural forces acting against the vehicle's motion, allowing for a smoother deceleration compared to a sudden stop.