Everday Words Used in Science

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Physical Science

End of Chapter Question Chapter 1

Page 36
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37


1


1.

Everday Words Used in Science

In everday speech, the words
precision
and
accuracy

are often used interchangeably. When these terms are used in science,
are their meanings the same as their everyday meanings?

Precision is the exactness of an answer while a
ccuracy is a description of how
close a measurement is to the true value of a measurement.


Using Key Terms

2.

Physical Science
was once defined as “the science of the nonliving world.”
Explain why that definition is no longer sufficient.

Today we tie in Ph
ysical Scienc
e with Chemistry and Biology, called
Biochemistry. It is not just the nonliving world.


3.

Explain why the observation that the sun sets in the west could be called a
scientific law.

Repeatedly day after day it does, so it is a law.


4.

Explain wh
y the following statement could be considered a
scientific theory:
The
rotation of Earth causes the sun to set.

It is a tested possible explanation of why the sun sets in the west.


5.

What is
mass
, and how does it differ from
weight
?

Mass is a quantity of m
atter, weight is a force that the Earth’s gravity pulls
on the matter.


6.

Some features on computer chips can be as small as 35 nm. Explain why you
would use
scientific notation

to express this quantity in meters.

It would be used because there would decre
ase the number of zeros.


7.

The mass of a certain elephant is 3,476 kg. A zoologist who measures the mass of
that elephant finds that the mass is 3,480 kg. Is the mass measured by the
zoologist
accurate
?

The mass is accurate because it is very close to the
very actual weight of the
elephant.


Understanding Key Ideas

8.

Which branch of science is not included in physical science?

D
. zoology

9.

Which science deals most with energy and forces?

B
. physics

10.

Using superconductors to build computers is an example of

A
.
technology

11.

A balance is a scientific tool used to measure

D
. mass

12.

Which unit is an SI base unit?

C
. kilogram

Physical Science

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13.

The composition of the mixture of gases that makes up our air is best represented
on what kind of graph?

A
. pie graph

14.

In a controlled experiment

C
. you change one variable throughout the experiment, and the other
variables remain fixed.

15.

Written in scientific notation, 0.000060 x is

B
. 6.0 x 10
-
5

s

16.

When studying a molecule, a chemist might make a model of the molecule to

B
. help visualize the mole
cule

17.

The maximum depth of a certain lade is 244 m. What is the depth of the lake in
kilometers?

B
. 0.244 km


Explaining Key Ideas

18.

Do scientific laws ever change? Explain.

Yes they can change if a new discovery cannot be predicted by a repeated
experiments

then the law may need to be modified to explain the new
discovery.


19.

Explain whether or not scientific methods are sets of procedures that scientists
follow.

They are not exact sets of procedures, they are only guidelines.


20.

Which variable is the dependen
t variable, and which variable is the independent
variable?

Dependent variable: temperature

Independent variable: time


21.

Why as this data presented in a line graph?

Because the temperature changed continuously with time during the
experiment.


Critical T
h
inking

22.

Applying Ideas

Today, scientists must search through scientific journals before
performing an experiment or making methodical observations. Where would this
step take place in a diagram of scientific methods?

Research and Data Collection step.


23.

Eva
luating Assumptions
At an air show, you are watching a group of sky divers
when a friend says, “We learned in science class that things fall to Earth because
of the law of gravitation.” What is wrong with your friend’s statement? Explain
your reasoning.

Th
e law of gravitation states that objects fall to the Earth and how to
calculate, but it does not explain WHY.

Physical Science

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24.

Applying Concepts
You report that a friend can go exactly 500 m on a bicycle in
39.46 s. But your stopwatch runs 2 s fast. Explain how your st
opwatch affects the
accuracy and precision of your measurement.

Because your stopwatch runs fast the time you measure is not accurate.
However your watch can measure somewhat precise.


25.

Bar Graphs
The bar graph below summarizes how a consumer magazine has

rated several stereos by price and sound quality. Use the graph to answer the
following questions.

a.

Which brand do you think has the best sound for the price?

Walsonic has the sound for the best price
.


b.

Do you think that sound quality is truly related to p
rice? Explain your
answer.

If sound quality and price were equal for all of the companies then sound
quality and price would be related. The graph shows that these two
properties change relative to one another depending on the company; so
sound quality and

price are not truly related.

26.

Pie Graph

The composition of silver solder is 40% silver, 40% tin, 14% copper,
and 6% zinc. Show this composition in a pie graph.


40
40
14
6




27.

Writing Scientific Notation

Write the following measurement
s in scientific
notation.

a.

22,000 mg





2.2 x 10
4

mg


b.

0.0000037 kg




3.7 x 10
-
6

kg


28.

Using Scientific Notation

Write the answers to the following calculations in
scientific notation.

a.

37,000,000 A x 7,100,000 s


2.6 x 10
14
As

Physical Science

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b.

0.000312 m
3

/ 486 s



6.4
2 x 10
-
7

m
3
/s



29.

Significant Figures

Round the following measurements to the number of
significant figures shown in parentheses.

a.

7.376 m (2)





7.4 m


b.

362.00306 s (5)



362.00 s



30.

Significant Figures

Write the answers to the following calculations. Be sure

to
use the correct number of significant figures.

a.

15.75 m x 8.45 m




133 m
2


b.

5,650 L / 27 min



210 L/min