Chapter 12, Problem 14TE

What physical principle is used by Manuel when he pumps in rhythm with the natural frequency of the swing?

To determine

The physical principle is used by Manuel when he pumps in rhythm with the natural frequency of the swing.

Answer to Problem 14TE

The high and low points will reinforce each other and get bigger, so it increases the oscillation .So it uses the principle of interference.

Explanation of Solution

A body has a fundamental frequency, the frequency at which the body will fluctuate consistently.

When a body is made to fluctuate such that the frequency of forced fluctuation is equal to the fundamental frequency of the body, the amplitude of fluctuation is greatly increased. This event is called resonance.

Well, it's a reinforcement of the vibration; the swinger's vibrations must constructively interpose with enhancing the amplitude of the wave. Suppose you have a couple of waves that are specifically identified and overlap each other. In that case, the high and low points will reinforce each other and get bigger, so it increases the oscillation.

Conclusion:

Therefore, the high and low points will reinforce each other and get bigger, so it increases the oscillation .So it uses the principle of interference.