Converting Metric Units

Aganack1

Senior member
May 16, 2002
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Hello I need to know how to conver 7.8 x 10^8 km^3 to mL. Any help would be great. Thanks
 

dullard

Elite Member
May 21, 2001
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I can't beleive that no one teaches how to multiply by 1 anymore. If you can do that, you can convert any units without difficulty.

For your problem you need to know this:

[*]7.8*10^8 km^3 = 7.8*10^8 km^3 * 1 * 1 * 1 * 1

If you can do that, you can answer your problem without google, and without help from others. In fact, you can use this for all of your other problems.

How? Well that is easy. There are 100,000 cm in 1 km. Or in other words:

1 = (100,000 cm / 1 km).

Now use this in the bulleted equation above:

[*]7.8*10^8 km^3 = 7.8*10^8 km^3 * (100,000 cm / 1 km) * (100,000 cm / 1 km) * (100,000 cm / 1 km)

Notice how the kilometers all cancel out? You are left with:

[*]7.8*10^8 km^3 = 7.8*10^23 cm^3.

Now use minendo's version of 1:

1 = (1 mL / 1 cm^3).

[*]7.8*10^8 km^3 = 7.8*10^23 cm^3 * 1 = 7.8*10^23 cm^3 * (1 mL / 1 cm^3) = 7.8*10^23 mL.
 

Aganack1

Senior member
May 16, 2002
331
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thank you dullard. I couldn't figure out what i was doing wrong but i get it now. Thanks again
 

DrPizza

Administrator Elite Member Goat Whisperer
Mar 5, 2001
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Originally posted by: dullard
I can't beleive that no one teaches how to multiply by 1 anymore. If you can do that, you can convert any units without difficulty.

For your problem you need to know this:

[*]7.8*10^8 km^3 = 7.8*10^8 km^3 * 1 * 1 * 1 * 1

If you can do that, you can answer your problem without google, and without help from others. In fact, you can use this for all of your other problems.

How? Well that is easy. There are 100,000 cm in 1 km. Or in other words:

1 = (100,000 cm / 1 km).

Now use this in the bulleted equation above:

[*]7.8*10^8 km^3 = 7.8*10^8 km^3 * (100,000 cm / 1 km) * (100,000 cm / 1 km) * (100,000 cm / 1 km)

Notice how the kilometers all cancel out? You are left with:

[*]7.8*10^8 km^3 = 7.8*10^23 cm^3.

Now use minendo's version of 1:

1 = (1 mL / 1 cm^3).

[*]7.8*10^8 km^3 = 7.8*10^23 cm^3 * 1 = 7.8*10^23 cm^3 * (1 mL / 1 cm^3) = 7.8*10^23 mL.

Agreed, but anyone seeking help in doing unit conversions might be better off multiplying by 100 cm/m and 1000m/km. It'd probably take a little more thought for them to use your 100,000 cm/km.

But, just keep multiplying by 1. As long as the numerator is equal to the denominator, the value of the fraction is 1. Keep at it until your units cancel out and you're left with the correct units.
 

dullard

Elite Member
May 21, 2001
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Originally posted by: DrPizza
Agreed, but anyone seeking help in doing unit conversions might be better off multiplying by 100 cm/m and 1000m/km. It'd probably take a little more thought for them to use your 100,000 cm/km.
I thought about it. But my post was long enough already. I didn't want to scare people away with too much math.

 

notfred

Lifer
Feb 12, 2001
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(7.8 * 10^8 km^3) * ((1000^3 m^3)/(1 km^3)) * ((100^3 cm^3)/(1 m^3)) * ((1 ml)/(1 cm^3))

That's how they teach you to do it in most chem classes.