SOLUTION: I'm having trouble trying to figure out how to set up the formula to solve a question asked to me. I was asked to figure out the mph of a skydiver free falling 7000 feet in 45 seco

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Question 7126: I'm having trouble trying to figure out how to set up the formula to solve a question asked to me. I was asked to figure out the mph of a skydiver free falling 7000 feet in 45 seconds. If you have any insight to this could you please assist me.
Answer by prince_abubu(198) (Show Source):
You can put this solution on YOUR website!
I think they're asking you to convert feet per second to miles per hour. We must begin with some facts and the belief that we can put equivalences in ratios.

5280 feet = 1 mile ----> or

3600 seconds = 1 hour ----> or

Step 1: Write the unknown variable x and then the label (which in this case, is miles per hour) on the left side of the equals sign. We are going to set up an equation.

=

Step 2: Choose the fraction written above that has miles on the numerator. This is the one that will convert feet to the miles.

Step 3: Now "put" the 7000 feet in 45 seconds ratio that they gave you to begin with, next to the (1 mile/5280 feet) ratio as a multiplication.

<---- This is called "forced chain-cancelling multiplication". We select the next fraction whose unit in the numerator is the same unit as the denominator in the fraction at the (former) end of the multiplication chain.

Step 4: The next fraction would be the one that has seconds in the numerator to match the seconds unit in the denominator of the (7000 feet/45 seconds) term.

Step 5: Cancel the units that match in the numerator and the denominator. We should be left with miles unit on the top and hour units in the bottom. Straight-up calculate using your calculator. You should finally get somewhere around 106.06 miles per hour.