제목...뭘로하지???

Understanding Doppler effect using a ripple tank

Doppler effect is the increase (or decrease) in the frequency of sound, light, or other waves as the source and observer move toward (or away from) each other.

There are many ways to demonstrate the Doppler effect but this one with a ripple tank is one of the most intuitive means to clearly understand the underlying concept.

* What is a ripple tank and what can you do with them ?

Never forget De Moivre’s formula

If you ever find yourself trying to remember any one of those basic trigonometric formulas, the ideal starting point is the De Moivre’s formula:

Above we have given you some examples of identities that can be easily derived using this formula. In fact, most trigonometric relations can be obtained from this formula after performing some basic algebra.