Physics 102 Physics of Music Test 2 Review Sheet Some basics related to the “mat
ID: 1785480 • Letter: P
Question
Physics 102 Physics of Music Test 2 Review Sheet Some basics related to the “mather" bits of class (yes, this is a skill you need all semester, not just from the first unit!) 1. Do you understand scientific notation? If you need a refresher, check out http://janus.astro.umd.edu/astro/scinote/. 1,000 103 since there are three zeroes, right? So 4,523 = 4.523 x 10°. As an aside, note that if you write 0.001 and count the zeroes, that tells you it's 1 x 10-3. So 0.000456 = 4.56 x 10-4. If you are in the habit of dropping that first zero, then not so much 2. Do you remember prefixes for basic units? Some of you didn't on the first test. Scientific notation might not be needed if you can write a number with the right units. So instead of 1,000,000 Hz, we can write 1 MHz (one MegaHertz), and instead of 0.00 000 1 s we can write 1 s (which is, by the way, the period if the frequency is 1 MHz). It's like the prefixes are a sneaky way around scientific notation.. 3. Do you understand how units “cancer, just like fractions? So that if, for some unfathomable reason, I want to know what the speed of sound is in the arcane units "furlongs per fortnight," I would set it up as follows, knowing the speed of sound in sea level air is about 345 m/s second m 39 inches1 yard 1 furlong 60s 60 min 24 hr 14 day S 345- 36 inches 220 yards 1 min 1hr 1 day 1 fortnight and then I can cancel every unit which appears both top and bottom leaving me furlongs per fortnight. The numbers would require a calculator, I suppose, so you won't have to do the actual numbers part on a test: just leave it ready for a calculator 4. If I just handed you some variables (such as, well,v, , T) and I told you what they physically represented, could you guess an equation that relates them? Could you check that your equation makes sense by making sure the units were the same on both sides? Try not to memorize!Explanation / Answer
1.
Scientific notation :
Scientific notation is a standard way of writing very large and very small numbers so that they are very easier to both compare and use in computations.
It has the form: N×10a
here N is a numbar between 1 and 10 but not 10 itself, a is an integer ( positive or negative)
For example 1243456 = 1.24× 106
0.000456 = 4.56×10-4