What was the belief about earth’s crust and landforms before the theory of plate tectonics?

Explain the doppler effect in terms of frequency, wavelength, and speed.

Asmall, positively charged ball is moved close to a large, positively charged ball. which describes how the small ball likely responds when it is released? it will move toward the large ball because like charges repel. it will move toward the large ball because like charges attract. it will move away from the large ball because like charges repel. it will move away from the large ball because like charges attract.

Anybody wanna ? (picture included? )