Question

newtons first law quick check
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? (1 point)
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
the car moves forward, while inertia keeps the balloon in place.
inertia prevents the force of the car from acting on the balloon.

Explanation:

Newton's first law states that an object at rest will stay at rest unless acted upon by an external force. When the car starts moving forward, the balloon (initially at rest) tends to stay in its original position due to inertia. The car moves forward, so relative to the car, the balloon appears to move backward.

• The first option is incorrect because there is no "unbalanced backward force" created by the car's motion on the balloon in the sense described.
• The second option is wrong as inertia is not a force, so there is no "force of inertia" balancing the car - motion - related force.
• The fourth option is incorrect because the car's motion does act on the air inside the car (which can indirectly affect the balloon), and inertia does not "prevent" the car's influence in that way.

Answer:

The car moves forward, while inertia keeps the balloon in place.