Question

Convert each rate using dimensional analysis. Round to the nearest tenth, if necessary.

55 mi / h = ____ ft / s
a.
8.7
c.
80.7
b.
26.9
d.
806.7

Answer 1

how many minutes makeup 1 hour?

Answer 2

60 minutes/hr. @Jhannybean

Answer 3

\[\cfrac{55 \ mi}{1 \ hr} \times \cfrac{ 1 \ hr}{60 \ min}\] So far. and we need to get to seconds.

Answer 4

\[\cfrac{55 \ mi}{1 \ \cancel{ hr}} \times \cfrac{ 1 \ \cancel{hr}}{60 \ min}\]

Answer 5

Now how many seconds are in 1minute?

Answer 6

Okay. Do we multiply those?

Answer 7

60 in 1

Answer 8

We are not done yet :P Just hang onto those numbers as they are for the time being.

Answer 9

Alrighty :D \[\large \cfrac{55 \ mi}{1 \ \cancel{ hr}} \times \cfrac{ 1 \ \cancel{hr}}{60 \ \cancel{min}} \times \cfrac{1 \ \cancel{min}}{60 \ sec}\]

Answer 10

Now we've got to convert our miles to feet... so how many feet are in 1 mile?

Answer 11

5280?

Answer 12

Good job.

Answer 13

\[\large \cfrac{55 \ \cancel{mi}}{1 \ \cancel{ hr}} \times \cfrac{ 1 \ \cancel{hr}}{60 \ \cancel{min}} \times \cfrac{1 \ \cancel{min}}{60 \ sec} \times \cfrac{5280 \ ft}{1 \ \cancel{mi}}\]

Answer 14

Are you with me so far?

Answer 15

Lol. I think so.

Answer 16

We have to logically place our conversions in the order of cancellation,much like we do with fractions, we want to cancel out the units to get to the conversion we are looking for.

Answer 17

Okay..Lol. I'm following..

Answer 18

Therefore, we have \[\large \cfrac{55(5280) \ ft}{60 \ sec}\]

Answer 19

4840

Answer 20

Yep, but it doesn't seem like one of your answer choices,so lets go back and check if we missed anything.

Answer 21

k.

Answer 22

Oh sorry, it's not divided by 60, it's divided by 3600.

Answer 23

[55(5280)]/3600

Answer 24

80.6?

Answer 25

it should say 80.67,not 806.7 .

Answer 26

Lol. 80.7

Answer 27

right? 80.7

Answer 28

Yep.

Answer 29

Thank you. (:

Answer 30

No problemo.