Testable hypotheses that lead to experiments usually describe a relationship between &
two measurable variables.
a measurable variable and a subjective opinion.
more than two subjective opinions.
more than two measurable variables.

What is the measurement of how fast an object moves relative to a reference point?

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.

What kind of waves require a medium to travel? question 6 options: light waves mechanical waves all waves need a medium to travel electromagnetic waves