Which explains the information needed to calculate speed and velocity?

Velocity is a vector quantity which means it has both magnitude and direction means in order to calculate it another vector quantity is used which is displacement on the other hand speed is a scalar quantity.

just here for the other one bc they put up with u

about 40,000,000 results (0.81 seconds)  

search results

what do the different brain waves do?

explanation:

brainwaves are produced by synchronised electrical pulses from masses of neurons communicating with each other. brainwaves are detected using sensors placed on the scalp. brainwave speed is measured in hertz (cycles per second) and they are divided into bands delineating slow, moderate, and fast waves.