Physics Help: Struggling w/Unit Conversion & Homework

  • Thread starter BunnyHanyou
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In summary, the conversation is about a student struggling with physics and unit conversions. They mention some specific conversion problems and ask for guidance. The responder suggests using SI units and provides resources and tips for converting units. They also mention the concept of 1 and provide a website for dimensional analysis.
  • #1
BunnyHanyou
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I Just Dont Get It!

Its my second day of physics and I have no idea what's going on -_- Its so riduculous We've started converting units and I am just completely lost I have 6 problems for homework and I am basically screwed :_[. Can someone please guide me through one or two of them? some of them are 286.6mm, 760mg, and 60.0ps please guide me through one or two :_[.
 
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  • #2
It seems like you are working with SI (MKS) units.

If so, is one supposed to convert each unit to its SI basis. For example, mm = millimeter, and the prefix 'milli' means 1/1000 th, or one-thousandth, and 1 mm = 1/1000 m = 0.001 m. The prefixes take the place of many 0's or scientific notation.

Another example, kg, which is kilogram. The prefix 'kilo' means 1000, and 1 kg = 1 kilogram = 1000 grams.

In the first example - 286.6 mm = 286.6/1000 m = 0.2866 m.

See - http://physics.nist.gov/cuu/Units/prefixes.html

and http://en.wikipedia.org/wiki/SI

and this is useful with some examples -
http://www.ebyte.it/library/educards/siunits/TablesOfSiUnitsAndPrefixes.html

a useful calculator
http://www.lenntech.com/unit-conversion-calculator/prefix.htm

Hyperphysics is a good general site -
http://hyperphysics.phy-astr.gsu.edu/hbase/units.html

Good for overchecking calculations
http://hyperphysics.phy-astr.gsu.edu/hbase/unitc.html#uc
 
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  • #3
One thing to remember also is the concept of 1; that anything divided by itself is 1. 1 foot/12 inches = 1. And that when you muliply 'anything' by 1 the 'anything' does not change. Then it is simply a matter of manipulating the units in the numerator or demominator.
 
  • #4
thats because you're dividing by 12 inches/ 1 foot so the feet cancel out.
 
  • #5
Unit conversion

Here's a site on dimensional analysis. http://www.chem.tamu.edu/class/fyp/mathrev/mr-da.html"

Good luck!
 
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FAQ: Physics Help: Struggling w/Unit Conversion & Homework

1. How can I convert units in physics?

Unit conversion in physics is a fundamental skill that involves converting a quantity from one unit to another. To convert units, you need to use conversion factors, which are ratios that relate two different units of measurement. For example, to convert meters to kilometers, you would use the conversion factor 1 km = 1000 m. Multiply the given quantity by the appropriate conversion factor to get the desired unit.

2. Why is unit conversion important in physics?

In physics, unit conversion is important because it allows us to express the same physical quantity in different units, making it easier to understand and compare measurements. It also helps us to solve problems and perform calculations more accurately, as different units may be needed for different equations or formulas.

3. What is the difference between SI and Imperial units?

SI (International System of Units) is a modern version of the metric system, which is the most widely used system of measurement in the world. It is based on seven base units: meter (length), kilogram (mass), second (time), ampere (electric current), kelvin (temperature), mole (amount of substance), and candela (luminous intensity). Imperial units, on the other hand, are a system of measurement primarily used in the United States and the United Kingdom. The most common imperial units are foot (length), pound (mass), and second (time).

4. How can I check my unit conversion calculations?

To check your unit conversion calculations, you can use dimensional analysis, which involves checking the units on both sides of the equation to make sure they are consistent. For example, if you are converting from meters to feet, the units on both sides of the equation should be in length units (meters on one side, feet on the other). Additionally, you can use an online unit converter or ask a classmate or teacher to review your work.

5. What are some common unit conversion mistakes to avoid?

Some common mistakes to avoid when converting units in physics include forgetting to include conversion factors, using the wrong conversion factor, and forgetting to convert the units for all the numbers in an equation. It is also important to pay attention to significant figures and round your answers appropriately. Always double-check your calculations and units to ensure accuracy.

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