On the project page on science buddies for the project I am doing (https://www.sciencebuddies.org/science- ... p036.shtml) in the procedure it states a conversion equation (Equations 5 and 6) where there is a confusing figure. It says to multiply everything by 1 km/1000 m. 1000 meters is one kilometer, so that would be 1. Am I supposed to multiply everything by 1, or by 1/1000? I don't know if the wording was wrong, or if I'm just not understanding it correctly.
Thank you!
Weird Equation
Moderators: kgudger, bfinio, Moderators
Re: Weird Equation
Hi. The information you are given (picture resolution) is in meters. In order to determine the height on Mercury, you must convert your numbers to kilometers. To do this, you divide your numbers by 1000, since there are 1000 meters in a kilometer.
Think of a basic fraction with multiple numbers in the numerator and denominator. Let's look at the fraction: (2*4) / (2*6). Since 2 is a common integer in both the numerator and denominator, you can cancel the 2's and are left with 4/6.
The same is true when setting up an equation to convert units. Look at equation 5. Why is the last fraction 1 km / 1000 m (divide by 1000) and not 1000 m / 1 km (multiply by 1000)? Set up your equation so that the same unit of measure is in both the numerator and the denominator, thus cancelling the unit. In equation 5, both pxl and meters can be cancelled out, since they appear in both the numerator and denominator, and you are left with just km as the unit of measure for your final calculation. You're not cancelling out the numbers associated with each unit...just the unit itself. If the last fraction was 1000 m / 1 km, then your unit of measure for your final calculation would be m^2 / km.
I hope this helps. Feel free to write back if you still have questions. Good luck!
Think of a basic fraction with multiple numbers in the numerator and denominator. Let's look at the fraction: (2*4) / (2*6). Since 2 is a common integer in both the numerator and denominator, you can cancel the 2's and are left with 4/6.
The same is true when setting up an equation to convert units. Look at equation 5. Why is the last fraction 1 km / 1000 m (divide by 1000) and not 1000 m / 1 km (multiply by 1000)? Set up your equation so that the same unit of measure is in both the numerator and the denominator, thus cancelling the unit. In equation 5, both pxl and meters can be cancelled out, since they appear in both the numerator and denominator, and you are left with just km as the unit of measure for your final calculation. You're not cancelling out the numbers associated with each unit...just the unit itself. If the last fraction was 1000 m / 1 km, then your unit of measure for your final calculation would be m^2 / km.
I hope this helps. Feel free to write back if you still have questions. Good luck!
Deana
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floringr
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- Project Question: Finding frictional force
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Re: Weird Equation
So for example, I have an image with 236 meters per pixel, and an image width of 1149 pixels. I would multiply 236 by 1149, which is 21164, then would I divide that by 1000 (giving me an answer of 67791/250)?
Re: Weird Equation
Besides a typo (236 * 1149 = 271164, not 21164), yes. That means the image height of the crater is approximately 271 km wide. Now do the same for height, and continue on with the steps.
Deana