Question

1. a measure of the amount number of waves that pass by in a given time is called

a trough
b frequency
c amplitude
d wave speed

Explanation:

Frequency is defined as the number of waves that pass a fixed - point in a given amount of time. A trough is the lowest point of a wave, amplitude is the maximum displacement of a wave from its equilibrium position, and wave speed is the speed at which a wave travels.

Answer:

B. Frequency