What is the conversion for 86.6 m to standard (base) SI units?

[kLPantera]

Homework Statement

Convert the following as full (decimal) numbers with standard (base) SI units:

86.6 m

The Attempt at a Solution

I thought I could just change it to 8.66x10^1 then just add the 10^-3 because of the milli to make it 8.66x10^-2. But I'm wrong so could someone help me?

 

[vela]

Did you mean 86.6 mm? I ask because 86.6 m is already expressed in meters.

 

[gerben]

What do you mean with: 86.6m?
Do you mean 86.6 meters?
If so, meters are SI units so you are done..

(milli is not a unit, it's a prefix of a unit, meaning a thousandth of that unit)

 

[kLPantera]

Sorry for the typo. I meant 86.6mm.

 

[vela]

Is this homework where you enter your answers on the computer? If so, what exactly did you type in for your answer?

 

[kLPantera]

it's a sheet of paper. I got this one now though. 86.6/1000 = 0.0866 which is 8.66E-2.
Except now I'm getting stuck on 45 microVolts. I don't know how to convert this one. What do you convert microVolts into? Volts?

 

[gerben]

Yes, Volt is an SI unit.

 

[vela]

it's a sheet of paper. I got this one now though. 86.6/1000 = 0.0866 which is 8.66E-2.

Which is the same as 8.66x10^-2, so why did you say it was wrong initially?

 

[kLPantera]

Ok I got it. My trouble is that I'm not sure what to convert it into. Like if it's mg I have to convert it go grams right? Or if it's pectoseconds I convert it to a minute? If fentometers then just to meters?

 

[kLPantera]

Which is the same as 8.66x10^-2, so why did you say it was wrong initially?

I said it was wrong initially because the way I derived it was wrong.

 

[vela]

Ok I got it. My trouble is that I'm not sure what to convert it into. Like if it's mg I have to convert it go grams right? Or if it's pectoseconds I convert it to a minute? If fentometers then just to meters?

No, you need to know what the base units are in SI. For mass, it's the kilogram; for length, it's the meter; and for time, it's the second. There's only one unit for each type of quantity, so all times are in terms of the second, not minutes or hours.

I said it was wrong initially because the way I derived it was wrong.

I wouldn't say what you did was wrong, at least based on how I interpret what you did. Multiplying by 10^-3 is the same as dividing by 1000. It's perfectly fine to think of it this way:

86.6 mm = 8.66x10¹ (10^-3 m) = 8.66x10^-2 m

In fact, it's often how I'll convert units rather than using the relatively long-winded way they teach in school.

 

[kLPantera]

Since the SI for time is seconds then, if it's 600 ps (pectoseconds right?) what else is there to convert to?

 

[vela]

ps stands for picoseconds. I assume you're supposed to express it in terms of seconds. Just like you converted millimeters to meters in the first problem, you want to convert picoseconds into plain old seconds.

 

[kLPantera]

I'm just getting really frustrated because I keep confusing myself for some reason.

Thanks for the help though, much appreciated.