Answers to CHPTR 2

2.3
a)centimeter
b)kiloliter
c)microliter
d)nanogram

.9
a)inexact
b)exactly
c)exactly
d)inexact

.11
i don't understand the question

.13
a)4
b)2
c)4
d)3
e)5
f)4

.23
a)5
b)4
c)3
d)4

.25
a)0.0080
b)1204.8
c)13.70
d)0.181
e)1.139
f)5.718

.27
a)162
b)9.321
c)1260.7
d)19.95

.29
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
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
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
1.6 x 10^2 m
2.4 x 10^-7 m
3 m
3.0 x 10^5 m

.47
183 lbs
6.29 ft

.53
243 grams

.65
a) 47.88 calories
b) 840 calories
c) 176.4 calories



3)
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)
Yes volume and mass are interchangeable
You can use the equation d=m/V to figure which is which, d stands for density

5)
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)
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)
10 = 1x10^1 = 10^1 = 10

8)
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)
2.56 cm^3 = 1 alien
9 x 2.56 = 23.04 cm^3

you need 23.04 cm^3 of granite

10)
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. 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. 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.