Firstly, I'd like to say sorry about the wonky spacing. I foodled around with it for about an hour and couldn't get the formatting to foodle my way. Secondly, sorry about the marks. Would you prefer that I teach you rather than reading out of the textbook?
2.3 4/4
a)centimeter
b)kiloliter
c)microliter
d)nanogram
.9 4/4
a)inexact
b)exactly
c)exactly
d)inexact
.11 0/2 The question is referring to uncertainty. If you had a thermometer that measured to each degree, then you would know the temperature to one tenth of a degree. Ie you know the temperature for sure - it's between 18 and 19. And then you have one further decimal place where the value is estimated. That is, you would know that it was around 18.5 by looking at the interval between 18 and 19 and estimating.
i don't understand the question
.13 4/4
a)4
b)2
c)4
d)3
e)5
f)4
.23 0/4 When multiplying and dividing, you should take the lowest number of significant digits, instead of the highest.
a)5
b)4
c)3
d)4
.25 1/6 The same applies here. Take the lowest number of significant digits
a)0.0080
b)1204.8
c)13.70
d)0.181
e)1.139
f)5.718
.27 2/4 When adding and subtracting, take the lowest number of digits from behind the decimal place, and this is the number of sig figs.
a)162
b)9.321
c)1260.7
d)19.95
.29 6/6 Great job here!
a)1.207 x 10^2
b)3.4 x 10^-3
c)2.3100 x 10^2
d)2.3 x 10^4
e)2.00 x 10^-1
f)1.011 x 10^-1
.35 4.5/6 Top marks for your use of scientific notation, but sig figs are still causing you trouble
a)5.504 x 10^12
b)4.144 x 10^-2
c)1.5 x 10^4
d)2.0 x 10^-7
e)1.52 x 10^11
f)1.2 x 10^6
.37 3/6 Although these are all true, a conversion factor is expressed in the form of a fraction so the conversion factors for a would be 1 g/0.001 kg and 1 kg/1000 g. They are expressed this way so that we can cancel out the unit we already have and get the unit we want. If we wanted to find the number of grams we have if we have two pounds, we phrase the equation this-aways:
2 lbs x 1 gram/0.002 lbs
This way since the lbs is both on the top and the bottom of the equation, we can cancel them out. What unit are we left with? Grams. This is good!
This same logic applies to equations. Let's say you didn't have a calculator and were expected to solve this problem:
3.145634001 x 6.7778203 x 1.2289667 x 4
3.145634001 x 6.7778203 x 1.2289667 x 2
Since all the really nasty terms apply on the top and on the bottom, they can be cancelled out! And you are left with only the 4/2 = 2.
a) 1g = .001kg 1kg = 1000g
b) 1nm = 10^-9 m 1m = 10^9nm
c) 1mL = .001L 1L = 1000mL
d) 1lbs = 454 grams 1 gram = .002 lbs
e) 1km = .621miles 1 mile = 1.61km
f) 1L = .265 gallons 1 gallon = 3.77L
.39 3/4 Question c
1.6 x 10^2 m
2.4 x 10^-7 m
3 m
3.0 x 10^5 m
.47 1.5/2 Rounding error. All of your answers are expressed to the correct number of significant figures! Very good!
183 lbs
6.29 ft
.49 0/1 You should have done this question!
.53 1/1
243 grams
.65 3/3
a) 47.88 calories
b) 840 calories
c) 176.4 calories
3) 1/2 While this is true, next time, I'd like more detail in the answer, such as why? What about mass does gravity not affect? What about weight does it affect?
This is because lbs is refered to as weight while grams are refering to mass. Gravity in space does not affect your mass, only your weight!
4) 3/3
Yes volume and mass are interchangeable
You can use the equation d=m/V to figure which is which, d stands for density
5) 2/3 Use sig figs to figure out the answer!
Essentially this is correct just that significant figures are being put to use, this is what it would look like cleaned up 793.5 km/hr
6) 1/3 Significant figures are important in calculating the trajectory of your spacecraft because it lets you know how accurately you know your position. Are you 1000 km from your destination or 1003.27 km from your destination? This allows you to calculate your trajectory more accurately. Scientific notation ensures that you do not drop or add zeros accidentally, thus changing the sun from being 150000000 km from earth to being a rather more toasty 15000000!
Significant digits are highly beneficial as they make searches for you ship that much more accurate, as for scientific notation it helps to remove clutter with big numbers.
7) 1/1
10 = 1x10^1 = 10^1 = 10
8) 2/5 Although you calculated the right answer, you did not include conversion factors in your answer.
ok first we should note that every four years is a leap year so with that
60 years have 365 days and 20 years have 366 days
60 x 365 + 20 x 366
21,900 + 7,320
therefore 80 years has 29,220 days
every day has 24 hours
29,220 x 24
701,280 hours
every hour has 60 minutes
701,280 x 60
42,076,800 minutes
every minute has 60 seconds
42,076,800 x 60
2,524,608,000 seconds
2.52 x 10^9 seconds
9) 1/2 Next time, please include conversion factors in your answer.
2.56 cm^3 = 1 alien
9 x 2.56 = 23.04 cm^3
you need 23.04 cm^3 of granite
10) 1/3 Next time, please include conversion factors in your answer!
I weigh 150 lbs which is equal to 68 kg
per .5 kg weight, 2 grams is lethal
per 1 kg, 4 grams
4 x 68= 272 g
it would take 272 grams of toxic evil salt to kill me, but then again i'll never die
11. 0/2 Next time, convert this temperature into Kelvin, as asked in the question. You wouldn't be dead honey, you'd be in an alternate universe. There is no such temperature as -274˚C, because absolute zero is -273.15˚C.
I can't read the thermometer, I'm dead, I mean frozen stiff (I can never die, refer to previous q) because its absolute zero.
Bonus. 1/1 Very good!
Awesome vid by the way, so what happens is that Helium becomes a superfluid, It can go through stuff simply because it has no thickness (or viscosity as they call it). To me it looks like the helium went from a gaseous state to this superliquid. I guess it never freezes.
Total chapter questions: 37/61 = 60.7%
Total assignment questions: 12/24 = 50.0%
Bonus: +1
Total: 50/85 = 58.8%
Comments: Ouch! That hurts!
If you want to bring this mark up, you can redo the assignment and get half of the full mark (ie a 0/6 -> 3/6). Let me know what you want to do.
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