how many sig figs ? 200 3.002.00034.7000 1 sig fig zeros are place holders 2 sig fig zeros are place...
TRANSCRIPT
1st PHYSICSHOMEWORK
HOW MANY SIG FIGS ?
200
3.002
.00034
.7000
1 sig figZeros are place
holders
2 sig figZeros are place
holders
4 sig figZeros are between
sig figs
4 sig figZeros are exact
zeros
HOW MANY SIG FIGS ?
3005
5.600
3000.0
1000
4 sig figZeros are between
sig figs
5 sig figLast zero is exact and others are in
between
4 sig figZeros are exact
zeros
3 sig figBar makes place
holders significant
Rounding to Sig Figs
670,239.286700,000
670,240670,239.3
1 sig fig
3 sig fig
5 sig fig
7 sig fig
670,000Need the bar to make the place holder significant
1. 1.55 x 106 nm = km
This is just a metric conversion ---- always 2 steps.
1.55 x 106 nm
Start with what you’re given:
One step to the BASE unit,
meters:
One step to the desired unit, kilometers:
x xnmm1x10-9
11 km
1x103 m
1.55x10-6 km3 sig figs
2. .00000093 Tg = g
This is just a metric conversion ---- always 2 steps.
.00000093Tg
Start with what you’re given:
One step to the BASE unit,
grams:
One step to the desired unit, micrograms:
x xTgg1x1012
11 g
1x10-6g
9.3x1011 g2 sig figs
3. 8.5 x 10-20 Ml = ml
This is just a metric conversion ---- always 2 steps.
8.5 x10-20 Ml
Start with what you’re given:
One step to the BASE unit, liters:
One step to the desired unit, milliliters:
x xMl
l1x106
11 ml
1x10-3 l
8.5x10-11 ml
Or you could use this for last fraction 1000 ml1 l
2 sig figs
4. 8 gallons = liters
Gallons is an English unit and liters is a metric unit - determine what Metric-English conversion will work (from box at top of homework)
8 gal
Start with what you’re given:
x xgalqt4
1.94 l 1 qt
30.08 liters1 sig figs
30 liters
5. 5.75 x 1015 s = years
5.75 x1015s
Start with what you’re given:
Keep converting to bigger units of time until you get to years:
x xs
min160
1 hr60min
1.82x108 yr
x x1 1days yr
hr days24 3653 sig figs
6. 500 ml/min = qt/hr
This has 2 dimensions. Convert ml to qt and min to hr
Start with what you’re given:
ml is on topMin on bottom
xml
l1x10-3
1
1 qthr
31.9 qt/hr
x x500 mlmin .94 l
60 min1
1 sig figs
30 qt/hr
7. 9 in2 = cm2
9 in2
Start with what you’re given:
Need 2 factors of inches to cancel inches squared
xin
cm
2.541
x 2.54 cm1 in
58.06 cm2
1 sig figs
60 cm2