For some reason I have really confused myself on how to do these homework assignments that are asking me to complete the conversions.

Here is one:
0.0001 MHz = ______Hz
What is throwing me off is that it is saying .0001Mkz. I am thinking that i would need to reduce this number to make it smaller since Hz is smaller than MHz so I am coming up with this number:
.1 x 10^-9

Am I doing this right? I don't get the feeling that I am doing this right? Could you send some hints my way?

 

Hello,

Have a look at this page:
http://www.simetric.co.uk/siprefix.htm

Bertus

 

Ok I have looked at the metric system prefixes and what is confusing me so much is the fact that it says 0.0001Mhz. I haven't had to deal with decimals like this before. When it says Mhz I think 1,000,000. But the way that my brain is telling me is that this is supposed to be 100μHz but it is in Mhz with μHz notation.

So if i follow the chart you provided i would need to get rid of 6 decimal places to make it 100Hz?

 

Hello,

Yes, 100 Hz is the correct answer.

Bertus

 

Ok, Thanks for the help. I know this is pretty easy, but I got myself all mixed up somehow and needed a push in the right direction again.

 

Use \(1M = 10^6\)

\(0.0001 = 10^{-4}\)

Hence \(0.0001M = 10^{(-4 + 6)} = 10^2 = 100\)

 

Here is one place where using the units can really help out. Here is one way to approach it:

\(
x Hz = 0.0001 MHz
\)

Your goal is to find the value of 'x' that makes this expression true and you will accomplish by multiplying the right hand side by values of 1 (so the value is not changed) but choosing how you express the value of 1 such that the units do change.

\(
x Hz = 0.0001 MHz \ \times \ \frac{10^6 Hz}{1MHz}
\)

Here we have just multiplied the right hand side by 1, since the numerator (10^6Hz) is equal to the denominator (1MHz).

\(
x Hz = (0.0001)(10^6) Hz \ \times \ \frac{1MHz}{1MHz}
\)

Here we have just rearranged factors, nothing more.

\(
x Hz = 100 Hz
\)

Here we have merely carried out the math and removed factors that cancel.

Another way to approach it is to treat the prefix as what it is, a multiplier separate from what it is multiplying:

\(
x Hz = 0.0001 MHz
x Hz = (0.0001)(M)(Hz)
x Hz = (0.0001)(M)(Hz) \times \frac{10^6}{M}
x Hz = \frac{(0.0001)(M)(Hz)(10^6)}{M}
x Hz = (0.0001)(10^6)(Hz)
x Hz = 100 Hz
\)