Somebody correct me if i’m wrong but here’s my problem. i had an 89.9 in science. so i retook a test i made an f on and got an a. shouldn’t my grade be a 90% or more! ?

Maybe but not necessarily. It could possibly bring it to a 90 or higher but it would also even out with the rest of your grades. Add them all up and divide by how many there are to determine what your average would be. If you have a school tool or schoology or something like that online, you can easily see your grades to do the math.

I hope this helped :)

From the info you provided yes..

Sound energy is produced when an object vibrates. examples are 1- a balloon popping2-a whistle3- a waterfall