A passenger in a moving car feels a jerk backward when the car suddenly starts. How does the first law of motion explain this experience?

The correct option is: The passenger tends to remain at rest while the car moves forward, showing inertia.

Step-by-Step Explanation:

1. Understanding Newton's First Law of Motion:
Newton's First Law of Motion, also known as the Law of Inertia, states that an object at rest will remain at rest, and an object in motion will continue to move at a constant velocity in a straight line, unless acted upon by an external net force. Inertia is the natural tendency of an object to resist any change in its state of motion.

2. Analyzing the Car and Passenger System:
Initially, before the car starts moving, both the car and the passenger are at rest relative to the road. Therefore, the passenger's body is in a state of rest.

3. What Happens When the Car Suddenly Starts:
When the driver accelerates the car forward, a force is applied to the car, causing it to move forward. The lower part of the passenger's body, which is in direct contact with the car seat, starts moving forward along with the car due to the frictional force exerted by the seat.

4. The Sensation of the Jerk Backward:
However, the upper part of the passenger's body is not rigidly attached to the car. Due to inertia, the upper body resists this sudden change and tends to maintain its original state of rest. As the car (and the lower body) moves forward, the upper body lags behind momentarily. This relative difference in motion makes the passenger feel as if they are being jerked or pushed backward, relative to the accelerating car.