Which of the following is the best example of a proper hypothesis? orange popsicles taste sweeter than grape popsicles. if two objects are dropped at the same height, the heavier object will hit the ground first. children who wear backpacks do better academically. i think there is no effect on hearing if you listen to loud music only three hours a day.

If two objects are dropped at the same height, the heavier object will hit the ground first.

Explanation:

A proper hypothesis has the form:

"If ... , then ... ".

Now, why the other sentence aren't hypothesis?

This sentence its an OPINION. It may be true that, for the speaker/writer, orange popsicles taste sweeter, but this is an subjective opinion, and difficult to test.

This sentence its an STATEMENT. If we wish to make an proper hypothesis, it should take the form:

If children wear backpacks, then they do better academically.

This sentence its another OPINION.  This opinion COULD be tested, but the proper way of write it as an hypothesis would be:

If someone listed to loud music only three hours a day, then there shoul be no effect on his/her hearing.

electrical power

one "light year" is the distance that light travels, through vacuum, in one julian year.   that's 365.25 days, of 24 hours each.