how many sig figs ? 200 3.002.00034.7000 1 sig fig zeros are place holders 2 sig fig zeros are place...

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1 st PHYSICS HOMEWORK

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Page 1: HOW MANY SIG FIGS ? 200 3.002.00034.7000 1 sig fig Zeros are place holders 2 sig fig Zeros are place holders 4 sig fig Zeros are between sig figs 4 sig

1st PHYSICSHOMEWORK

Page 2: HOW MANY SIG FIGS ? 200 3.002.00034.7000 1 sig fig Zeros are place holders 2 sig fig Zeros are place holders 4 sig fig Zeros are between sig figs 4 sig

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

Page 3: HOW MANY SIG FIGS ? 200 3.002.00034.7000 1 sig fig Zeros are place holders 2 sig fig Zeros are place holders 4 sig fig Zeros are between sig figs 4 sig

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

Page 4: HOW MANY SIG FIGS ? 200 3.002.00034.7000 1 sig fig Zeros are place holders 2 sig fig Zeros are place holders 4 sig fig Zeros are between sig figs 4 sig

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

Page 5: HOW MANY SIG FIGS ? 200 3.002.00034.7000 1 sig fig Zeros are place holders 2 sig fig Zeros are place holders 4 sig fig Zeros are between sig figs 4 sig

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

Page 6: HOW MANY SIG FIGS ? 200 3.002.00034.7000 1 sig fig Zeros are place holders 2 sig fig Zeros are place holders 4 sig fig Zeros are between sig figs 4 sig

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

Page 7: HOW MANY SIG FIGS ? 200 3.002.00034.7000 1 sig fig Zeros are place holders 2 sig fig Zeros are place holders 4 sig fig Zeros are between sig figs 4 sig

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

Page 8: HOW MANY SIG FIGS ? 200 3.002.00034.7000 1 sig fig Zeros are place holders 2 sig fig Zeros are place holders 4 sig fig Zeros are between sig figs 4 sig

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

Page 9: HOW MANY SIG FIGS ? 200 3.002.00034.7000 1 sig fig Zeros are place holders 2 sig fig Zeros are place holders 4 sig fig Zeros are between sig figs 4 sig

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

Page 10: HOW MANY SIG FIGS ? 200 3.002.00034.7000 1 sig fig Zeros are place holders 2 sig fig Zeros are place holders 4 sig fig Zeros are between sig figs 4 sig

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

Page 11: HOW MANY SIG FIGS ? 200 3.002.00034.7000 1 sig fig Zeros are place holders 2 sig fig Zeros are place holders 4 sig fig Zeros are between sig figs 4 sig

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