Unit Conversion Help

[LCKurtz]

Back in the stone age I was taught to use the "dimensional unit method" in a chemistry course for such problems. It may be the only thing I remember from that course in 1959. But it is very handy for keeping track of where you are in such a problem. Below is how this problem would be set up:
$$x \frac{ \text{ teragrams}}{\text{Funville year}} = \frac {23.6568988\text{mg} }{1\text{meter}^2\cdot1\text{sec}}\times \frac {31,536,000\text{sec}}{1\text{year}}\times \frac {390,200,000\text{meter}^2}{1\text{Funville}}\times\\ \frac{1\text{teragram}}{1,000,000,000,000,000\text{mg}}$$If I didn't make any mistakes, the units on the right side will cancel to match those on the left.

 

[LCKurtz]

29110635340926336 * 100,000,000,000,000,000 [mg/y *teragrams/ y] = 2911063534092633600000000000000000 teragrams/y ?

If you look at my post #21 and calculate it you will get approx. 2.911 teragrams. You are a few decimal places off.

 

[melodys]

Back in the stone age I was taught to use the "dimensional unit method" in a chemistry course for such problems. It may be the only thing I remember from that course in 1959. But it is very handy for keeping track of where you are in such a problem. Below is how this problem would be set up:
$$x \frac{ \text{ teragrams}}{\text{Funville year}} = \frac {23.6568988\text{mg} }{1\text{meter}^2\cdot1\text{sec}}\times \frac {31,536,000\text{sec}}{1\text{year}}\times \frac {390,200,000\text{meter}^2}{1\text{Funville}}\times\\ \frac{1\text{teragram}}{1,000,000,000,000,000\text{mg}}$$If I didn't make any mistakes, the units on the right side will cancel to match those on the left.

I haven’t heard of this method before thank you so much I will make sure to add to my note

 

[Steven G]

I haven’t heard of this method before thank you so much I will make sure to add to my note

Do those fractions equal 1??

 

[melodys]

Do those fractions equal 1??

No so I will add a 1 to them

 

[Steven G]

No so I will add a 1 to them

If you add 1, then the sum will change. For example if you add 1 to 5, you get 6 (not 5). If you add 1 to 14, you get 15.
You can not add 1 and expect equality (5 ≠ 5+1).
However, you can multiply by 1 and the value does not change.