Question

hot - air balloons are based on a single concept: warm air rises and cool air falls. this is because cold air is denser than warm air. density is defined as the ratio of mass to volume; it tells us how many molecules occupy a space at one time. the more molecules there are in a given volume, the denser the substance. the fewer molecules there are, the less dense the substance is. warm air, in which the molecules are farther apart, is less dense than cold air. for liquids and gases, a substance that has greater density sinks to the bottom of a mixture, a less - dense material rises to the top. this is the science that powers hot - air balloons. heating up air inside the balloon makes that air less dense than air outside the balloon, and the air—along with the balloon—begins to rise. differences in density are what makes a hot - air - balloon ride possible. what does the word detect mean as it is used in paragraph 6? 1. absorb 2. change 3. eliminate 4. find

Explanation:

In the context of the paragraph about hot - air balloons and density, the word "detect" means to find. It is related to how science helps in understanding the principles that allow hot - air balloons to function, such as differences in density.

Answer:

1. find