SOLUTION: This is for my 12 year old nephew in the 7th grade. This question is off of a worksheet. The question is: You can use the expression 5M to find out how many seconds it takes a

Algebra ->  Equations -> SOLUTION: This is for my 12 year old nephew in the 7th grade. This question is off of a worksheet. The question is: You can use the expression 5M to find out how many seconds it takes a      Log On


   

Question 50885: This is for my 12 year old nephew in the 7th grade. This question is off of a worksheet. The question is:
You can use the expression 5M to find out how many seconds it takes a sound to travel M miles through the air. However, through water sound takes M seconds to travel M miles. Use an expression like 5M-M to find out how much longer it will take sound to travel 8 miles in air than in water.
Thanks!
Answer by darq(90) About Me  (Show Source):
You can put this solution on YOUR website!
so sound travels 5 time faster in the water which means that it will take 5M time rather than M time to travel through the air.
if we are talking about a 8 times longer way it will take 40M in the air, 8M in the water.
subtract the 8M from 40M to see the difference; that is 32!
32M - 8M or you can use this; 8(4M-M)