A balloon floats inside a stopped car. When the car starts moving forward, the balloon appears to move backward relative to the car. Which statement best explains this observation? Inertia prevents the force of the car from acting on the balloon. The car moves forward, while inertia keeps the balloon in place. The motion of the car creates an unbalanced backward force on the balloon. The force of inertia on the balloon balances the force from the motion of the car.

Answer 1

The best explanation for the observation that the balloon appears to move backward relative to the car when the car starts moving forward is: "The car moves forward, while inertia keeps the balloon in place."

This explanation highlights the concept of inertia, which is the tendency of an object to resist changes to its state of motion. When the car accelerates forward, the balloon, due to its inertia, tends to remain in its original position (at rest relative to the ground) for a moment. As a result, it appears to move backward relative to the accelerating car.