Chapter 7, Problem 48A

A balloon floats motionless in the air. A balloonist begins climbing up the supporting cable. In which direction does the balloon move as the balloonist climbs? Explain.

To determine

The direction which the balloon moves as the person climbs the rope.

Explanation of Solution

Introduction:

Newton’s third law states that to every action there is always an equal and opposite reaction. A tension in a rope when it is pulled is an example of Newton’s third law.

When the balloonist climbs the motionless balloon, he applies a force in the downwards direction to climb. By Newton’s third law, an equal reaction force (tension) is created which is in opposite direction, i.e.,upwards on the balloonist. Hence, the balloon is pulled down by balloonist when the balloonist climbs up the rope.

Conclusion:

The balloon is pulled down by the balloonist when the balloonist climbs up the rope.