Question

https://postimg.org/image/hygqnxz4d/

Can someone help me fully understand this multiple step conversion?

This is what I have so far

80m/h x 1h/60m x 1min/60sec=80m/60sec

I'm not sure if that's correct, but if it is, I don't know where to go from there.

I tried doing

80m/60sec x 5280ft/1m= 80x5280/1m but I got a crazy answer, and decided not to continue since I figured I was doing it wrong.

I'm also confused because why at the very end are we doing 1meter/100cm?

Since the conversions are going down by which one is bigger, shouldn't 1meter/100 cm be at the beginning?

Answer 1

@mww

Answer 2

why not simplify `80m/60sec` before you go any further?

by the way, that should be 80/3600 since there are two copies of 60 being multiplied

Answer 3

miles to ft to in to m is very tedious.
miles to km then m is far better

Answer 4

and yes as jim thompson pointed out

it is 80 miles/(60 x 60 seconds)

Answer 5

Please consider finding some other way of capturing images from your computer screen. The " https://postimg.org/image " that you're using now is primarily an advertising site, and the advertisements are NOT suitable for young students.

Answer 6

Oh, will do.

@jim_thompson5910

I don't quite understand why it should be 80/3600 yet

Answer 7

because 60*60 = 3600 @Kikuo

Answer 8

I recommend this pathway:

1) miles/hr --> miles/second (divide by 3600 since 1 hr = 60 min = 60 x 60 =3600 seconds)
2) miles/second --> km/second (multiply by 1.609 since there are 1.609 km per mile)

3) km/second --> m/second (multiply by 1000 as there are 1000m/km)

Answer 9

I will note that as an Australian, I use the metric system which is much simpler for me than miles/ft/inch conversions. Americans may use imperial measures more frequently.

Answer 10

Ha, that does seem easier, but I would like to use this pathway simply so I know that I can solve it.

: )

Answer 11

well it's the same deal really, just have more conversion steps (so you need to know what conversion ratios are for each step)

Answer 12

Well, I'm lost on two things.

Why is it 80/3600 is the first thing.

Answer 13

Oh, wait, didn't see jim's post.

Answer 14

@jim_thompson5910

Oh, I see now.

Alright. That makes sense.

So, now we have 80/3600

I believe I know how 80 x 5280/3600

Right?

Answer 15

why not reduce 80/3600 first?

Answer 16

fractions are a pain to deal with but reducing them as much as possible should make them a bit easier to handle

Answer 17

Reducing them to make one quantity?

What would the quantity unit be though?

Miles? Feet?

I guess you can say I haven't reduced them when converting yet because I'm not sure what it would look like

0.022x5280ft/1mile?

Answer 18

one thing you can do is knock off a pair of 0s

80/3600 = 8/360

then you can divide each part by the GCF 8

8/8 = 1
360/8 = 45

so 8/360 = 1/45

which means

80/3600 = 1/45

Answer 19

80 m/3600 sec = 1 m/45 sec

in 45 seconds, you travel 1 meter

Answer 20

Why could knock off the pair of 0s like that?

Also without reducing this is what I have without reducing

80/3600 x 5280ft/1mile= 422,400 ft /3,600 miles x 12 in/ 1 ft= 5,068,800 in/ 3600ft x 2/54 cm/ 1=12,874,752/3600 inches x 1meter/100cm= 12,874,752 meters/360,000 cm

I'm not sure if it's supposed to be 12,874,752/360,00 sec or cm

I assume I divide from there

Answer 21

it's a shortcut to divide

for example

100/10 = 10/1 = 10

the right most '0' can be canceled

Answer 22

Oh I see.

I understand now.

It's like reducing 10/1000 to 1/100 I assume.

Also, for my above answer, is it seconds or cm, and do I divide?

Answer 23

Oh, for the final answer, I got 12,874,752 meters/360,00 centimeters.

Is this right or should the denominator be seconds?

As in meters/seconds

Answer 24

@Kikuo what's the original problem and instructions?

Answer 25

Which is faster, going 80 miles an hour or going 40 meters per second was the original question.

As for the instructions, I showed in my screenshot the path they wanted us to take to convert 80 miles/1 hour to meters/second.

Answer 26

@jim_thompson5910

Answer 27

ok let me look it over again

Answer 28

ok I agree with you getting 12,874,752/360,000

you will have meters in the numerator and seconds in the denominator

your screenshot shows which units will cancel an which units stay behind

also 12,874,752/360,000 = 35.7632
which is what your screenshot is saying

Answer 29

80 mph = 35.7632 meters per ssecond approximately

So the answer to "Which is faster, going 80 miles an hour or going 40 meters per second?"
is the "40 meters per second"

Answer 30

@jim_thompson5910

I'm a bit confused.

How did we get 35 meters per second

Out of 12,874,752 meters/360,000 cm

Is the denominator supposed to be seconds?

Answer 31

@mww

Since he left.

Answer 32

Oh wait, I figured out why it was 12,874,752 meters/360,000 seconds

Following the chart wrong haha

Alright one last question

Answer 33

the fraction is something metres / something seconds so the eventual units are metres/secon

Answer 34

That makes sense now.

Can you explain why they have 1 meter/100 cm at the end in the original picture?

Since meters are bigger than feet and inches I expected 1 meter/100 cm to be further at the front, but it's at the end.

Why?

Answer 35

What I'm asking basically is why did we go from

Miles to feet, feet to inches, inches to cm, and then cm to meters.

I understand all of it except why we went to cm to meters.

Answer 36

I figured it out!