A hot air balloon begins its descent at a rate of 22#1/2# feet per minute. How long will it take for the balloon' s elevation to change by —315 feet?

1 Answer
Nov 8, 2015

It will take 14 minutes for the balloon to descend 315 ft.


This question requires knowledge of the Speed formula (#s=d/t#). Where:
s = speed
d = distance
t = time

You are given a speed of -22.5 feet per minute and a distance of -315 feet. If you plug these values in you get the following equation:

#-22.5 (ft)/min = (-315 ft)/t#

You then re-arrange the formula to solve for time:

#t = (-315ft)/(-22.5 (ft)/min)#

When you solve this formula, the feet and negative signs will cancel out leaving positive minutes as your unit. Dividing 315 by 22.5 gives you 14 as your number.

Therefor your answer is 14 min.