Sci meas review
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Transcript Sci meas review
Scientific Measurement
Did you do your homework?
44 points possible!
The team with the most points at
the end of the period wins!
The wining team will receive 10 pts
extra credit on their assignment
sheets.
Let’s Play!
Accuracy and Prcesion
Describe the accuracy and precision of
each student’s measurement, the correct
mass is 47.32 g.
Trial
Lissa
Lamont
1
2
3
4
47.13
47.94
46.83
47.47
47.45
47.39
47.42
47.41
Leigh
Anne
47.95
47.91
47.89
47.93
Answer
Lissa – inaccurate and imprecise
Lamont - accurate and precise
Leigh - Anne inaccurate and precise
Maximum 3 points
Significant Figures
a.
b.
c.
d.
How many in each?
60s = 1min
47.70 g of copper
1 km = 1000m
25 computers
Answer
a.
b.
c.
d.
Infinite
4 sig figs
Infinite
Infinite
4 points
Round off to 3 Sig Figs
a.
b.
c.
d.
98.473
0.00076321 cg
57.048 m
12.17 oC
Answer
a.
b.
c.
d.
98.5
0.000763
57.0
12.2
4 points
Sig Fig Rules for Calculations
Round of each of the answers
correctly.
a. 8.7 + 15.43 + 19 = 43.13
b. 853.2 – 627.443 = 225.757
c. 38.742 / 0.421 = 92.023
d. 5.4 x 3.21 x 1.871 = 32.431914
Answer
a.
b.
c.
d.
43
225.8
92.0
32
4 points
Metric Conversions
a.
b.
c.
d.
e.
f.
Make the following conversions
157 cs = ? s
42.7 L = ? ml
261 nm = ? mm
0.065 km = ? dm
642 cg = ? Kg
8.25 x102 cg = ? ng
Answer
a.
b.
c.
d.
e.
f.
1.57 s
4.27 x 104 ml
2.61 x 10-4 mm
650 dm
0.00642 kg
8.25 x 109 ng
6 points
Density
Would the density of a person be the
same on the surface of Earth and
on the surface of the moon?
Explain.
Answer
Yes, neither the mass nor volume of
the person would change when
they went to the moon, so the
density (m/v) would remain the
same.
5 points
Scientific Notation
Rank these numbers from
smallest to largest.
a. 5.3 x 104
b. 57 x 103
c. 4.9 x10-2
d. 0.0057
e. 5.1 x 10-3
f. 0.0072 x 102
Answer
e, d, c, f, a, b
3 points
Density
The density of dry air measured at 25 oC
is 1.19 x 10-3 g/cm3. What is the volume
of 50.0 g of air?
D = m / V, so V = m / D
V=
5 points
50.0 g
= 4.20 x 104
1.19 x 10-3 g/cm3
Density
A tank with volume, 28.6 cm by 73.0
mm by 0.72 m is filled with olive oil.
The oil in the tank has a mass of
1.38 x 104 g. What is the density of
the olive oil in kilograms per liter?
Answer
First find the volume:
28.6 cm x 7.30 cm x 72 cm
= 15032.16 cm = 15000 cm3
Second find the density:
1.38 x 104 g / 15000 cm3
= 0.92 g / cm3
= 0.92 kg / L
10 points