If 20 beats are produced within one second, which of the following frequencies could possibly be held by two sound waves traveling through a medium along a common path at the same time?

a. 38 hz and 63 hz
b. 22 hz and 42 hz
c. 47 hz and 55 hz
d. 18 hz and 26 hz

Which types of electromagnetic waves have higher frequencies than the waves that make up ultraviolet light? check all that apply. radio waves infrared light microwaves gamma rays visible light x-rays

The least penetrating form of radiation is

Why is rain likely when warm, moisture-laden air meets cold air? a) the lighter warm air will rise and cool down, causing condensation and rain. b) the cold air moves faster and pushes the warm air away, causing condensation and rain. c) the moisture in the warm air condenses on contact with the cold air, causing rain to fall. d) the cold air mixes with the warm air, reducing its temperature causing moisture to condense.