You visit the grand canyon on a particularly hot day, and like all good tourists, you yell "hello! ". would you expect to hear the echo sooner or later than on a cooler day? why?

Hear echo sooner on a hot day than on a cooler day.

Explanation:

Temperature is one of the factors that determine the speed of sound. Speed of sound, which in this case is echo is calculated considering distance and time. Speed of sound is directly proportional to the temperature , therefore, when the temperature is hot, the speed of sound is faster than when the temperature is cold and vice versa. In conclusion, you would expect to hear the echo “hello” sooner on a hot day compared to a cold day provided all the other factors are kept constant.

false

explanation:

boats, things on boats luggage are way more heavy then water.

i am pretty sure it is c because when people are closer together, they cannot move as freely. picture being in a mostly full elevator, for instance. the people are right next to you, and you can barely move.