Q: What effect, related to weather forecasting, occurs not only for sound but for any wave when there is relative motion between the observer and the source?


Read this paragraph and choose the correct option from the provided answers:

Mole-mole calculations are not the only type of calculations that can be performed using balanced chemical equations. Recall that the molar mass can be determined from a chemical formula and used as a conversion factor. We can add that conversion factor as another step in a calculation to make a molemass calculation, where we start with a given number of moles of a substance and calculate the mass of another substance involved in the chemical equation, or vice versa. For example, suppose we have the balanced chemical equation.

 Choices:

- pulse

- echo

- precipitation

- doppler


A:
doppler