BLM 4-AnsKey.pdf

CHAPTER 4 ANSWER KEY
BLM 4-1, Steam Engine Designs/
Overhead Master
Answers
not applicable
BLM 4-2, The Changing Face of the
Steam Engine/Skill Builder
Goal: Students develop a detailed understanding of some
steps in the evolution of the steam engine.
Answers
1. The fire caused the water in the kettle to boil. When
the liquid water turned into steam, its volume
increased and the steam was pushed up the two pipes
that supported the hollow ball above the kettle. The
only way for the steam to escape from the hollow ball
was through the curved pipes on the sides of the ball.
As the steam was pushed out of the curved pipes, it
pushed back so hard that it made the pipes and,
consequently, the ball move in the opposite direction
to the steam. Since the ball was attached to an axle,
the ball rotated when the steam pushed out of the
curved tubes. This motion is similar to the movement
of a balloon that has been blown up and released.
2.
- - - - - The water boiled into steam. Valve C was opened,
and the steam went into vessel D.
· · · · · · Valve C was closed and valve V1 was opened.
The steam condensed back into water, creating a
vacuum in vessel D. The vacuum above the water in
the lower pipe exerted less pressure on the water in the
mine than did the atmosphere above the water outside
the pipe. As a result, the atmospheric pressure pushed
the water up the pipe into vessel D.
⎯⎯⎯ Valve V1 was closed and valves C and V2
were opened. Steam from the boiling water now
pushed the water out of vessel D and up pipe E to G,
where it was expelled.
3. During the second step in the cycle of Savery’s steam
engine, when a vacuum formed in the vessels labelled
D in the diagram, atmospheric pressure above the
water in the mine pushed the water up the pipe into
the vessels.
4. During the last step in the cycle of Savery’s steam
engine, steam pressure from the boiler pushed the
water in the vessels labelled D up the pipes labelled E
to pipe G, where it was expelled.
5. (a) When steam was allowed into the cylinder, the
steam pressure below the piston was greater than
the atmospheric pressure above the piston,
causing the piston to rise.
(b) When the valve to the boiler was closed and water
was sprayed into the cylinder, the cylinder was
cooled. The lowering of the temperature caused
the steam to condense. The condensing of the
steam reduced the pressure below the piston.
Then the atmospheric pressure above the piston
was higher than the pressure inside the cylinder.
The atmospheric pressure thus pushed the piston
down.
6. The cold water was needed in Newcomen’s steam
engine to cool the piston and condense the steam, thus
creating a vacuum.
7. In Watt’s steam engine, steam pressure pushed the
piston both ways. Since steam acted on the piston
twice in one complete cycle, the engine was called a
“double-acting” engine.
8. The valve in Watt’s steam engine moved one way to
direct the steam to one side of the piston and then
moved the other way to direct the steam to the
opposite side of the piston.
9. Since the cylinder in Watt’s steam engine was always
hot, the cylinder and piston were not subjected to
frequent heating and cooling. In steam engines that
were used before Watt developed his engine, extreme
changes in the temperature of the metals caused the
metals to expand and contract. This resulted in serious
wear and tear on the parts.
10. Watt invented systems of levers and a crank shaft that
allowed the steam engine to turn a large wheel. A belt
connected the wheel of the engine to other wheels,
which could run many types of machines.
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CHAPTER 4 ANSWER KEY
Extend Your Skills
11. Since over 70 of the devices that were sketched by
Hero can be found on the Internet, students’ answers
will vary. One of the interesting devices is shown
here. When a fire is lighted on the altar, it heats the air
in the altar. A rod passes down into the water in the
base of the pedestal. The heated air expands and
moves into the water. The extra pressure pushes the
water up, through pipes in the statues to the vessels in
the statues’ hands. The water pours out from the
vessels and extinguishes the fire on the altar.
12. Metals expand and contract when heated and cooled.
When metal parts that are connected expand and
contract, the connections can be damaged. Spacers are
built into structures such as bridges. When the metal
parts expand or contract, the spacers are designed to
open further or close. This design prevents excessive
stress and strain on the metal parts as well as concrete.
BLM 4-3, Science, Technology, and the
Industrial Revolution/Science Inquiry
Goal: Students clearly understand the impact that a new
technology, the steam engine, had on society and the
environment.
Answers
Answers will vary depending on the sources. Below are
some possible answers that students might find on the
Internet or in print resources.
Child Labour
1. Children worked in textile mills, changing spools and
operating the machinery. They worked in breaker
rooms of coal mines, sorting and breaking pieces of
coal. They worked in glass factories, holding molds.
They also worked in canneries.
2. In the early days of the Industrial Revolution, it was
common for children as young as seven years old to
work in factories.
3. In the early days of the Industrial Revolution, children
worked up to 18 h a day, six days a week. They
typically earned about one dollar a week.
4. By the late 1800s, many laws were passed that were
intended to improve working conditions and prevent
child labour. However, these laws were often ignored.
It was not until the late 1930s that laws were passed
and enforced in North America to limit the number of
work hours and prevented child labour.
Working Conditions
1. In the early 1800s, factory labourers worked from 12
to 18 h a day, six days a week.
2. Children earned about one dollar a week. Adults
earned four or five dollars a week.
3. The air in textile mills was filled with lint, which
could cause respiratory diseases. The large, heavy
machines were not protected. Children might dose off
and fall and be injured by a machine. The factories
were cold and drafty in the winter and hot and humid
in the summer. Stonemasons lived, on average, to only
36 years of age due to breathing the dust.
4. Methane gas could collect in a coal mine and explode.
Ground water could seep into a mine and trap miners.
Breathing coal dust caused serious respiratory
damage.
5. It was not until about 1910 that safety in the
workplace became a social issue. Significant changes
in workplace safety took place between 1910 and
1929. When laws were passed to compensate workers
who had been injured in the workplace, factory
owners began to improve safety conditions.
6. The 8 h workday was discussed by some reformers in
the mid-1800s. It was not until the 1950s, however,
that the 40 h workweek was generally accepted
throughout North America and Europe.
7. One of the first mine safety laws was passed in 1891.
These first laws were not strict but have been
improved, step by step, over the years.
Pollution
1. Refuse from mines, solvents from textile dyeing,
cleaning and tanning solvents from leather tanning,
garbage from slaughterhouses, and sewage were
dumped directly into rivers during the early years of
the Industrial Revolution.
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be held responsible for content if any revisions, additions, or deletions are made to this page.

CHAPTER 4 ANSWER KEY
2. The famous physicist Michael Faraday wrote a very
poignant letter to the editor of a newspaper, describing
the filth of the River Thames in London. Ellen
Swallow Richards (1842–1911), the first woman to be
accepted into MIT (Massachusetts Institute of
Technology), was an early campaigner for clean
water. She earned a degree in chemistry and carried
out tests on water purity.
3. Several laws were passed in the 1860s and 1870s in
Europe and North America, limiting air and water
pollution.
BLM 4-4, Using GRASP to Solve
Problems/Reinforcement
Goal: Students develop a structured thinking process that
will help them solve problems.
Answers
1. Answers will vary but should follow the general steps
in the sample answer below.
Given: Will be jogging outside today
Will be going for job interview after
school
Forgot to do laundry
Required: Must be dressed for both jogging
outside and going to a job interview
Analysis: Clothing must be clean. It must be
comfortable and cool for jogging, and
neat for interview. Layered clothing
will permit comfort and neatness.
Solution: Wear T-shirt with good shirt or light
sweater over it. Take off shirt or sweater,
and jog in T-shirt. Wear nice pants, not
jeans. Pants must be loose enough for
jogging and neat enough for interview.
Paraphrase: Wear T-shirt and loose pants for
jogging. Add good shirt or light
sweater for interview.
2. Answers will vary but should follow the general steps
in the sample answer below.
Given: Critical exam in required course
tomorrow
Must pass course to take sequential
course next year
Future plans require passing these
courses
Friends practising favourite sport
Tryouts in three days
Making varsity team will help achieve
plans for coaching career
Required: Must decide what is most beneficial for
being accepted into university program
in coaching
Analysis: Is it possible to practise with friends
and then study enough to pass the exam
tomorrow? Which is more critical for a
future career in coaching: passing the
exam or making the varsity team?
Decide not to take chances.
Solution: Stay home and study. If you don’t pass
the courses you need, making the
varsity team will have little influence
on getting into the university program.
Paraphrase: Stay home and study.
3. Given: Must raise $1000
Have $275
Earn $8.50/h
15% withheld for taxes
12 h worked per week
Time remaining Dec. 1 to Oct. 1
Required: $1000 by Dec. 1
Analysis: Determine number of hours to be
worked by Dec. 1 to get money earned
by Dec. 1. Add money earned to
amount already in bank, and compare
total with $1000 needed.
Solution: Days in October = 31
Days in November = 30
Total days remaining = 61
Weeks remaining =
61 days
8.7 weeks
7 days per week =
Work hours = 8.7 weeks × 12 h/week =
104.4 h ≈ 104 h
Money to be earned = 104 h × $8.50/h
= $884
Money to be earned minus taxes
withheld = $884 − ($884 × 0.15)
Money to be earned minus taxes
withheld = $884 − $132.60
Money to be earned minus taxes
withheld = $751.40
Money earned plus savings = $751.40
+ $275
Money earned plus savings = $1026.4
$1026.4 is greater than $1000.
Paraphrase: You will have $26.40 more than you
need for the trip. You can go!
4. Given: Distance to bus = 20.8 km
Time to reach bus = 20 min
Speed limit for 8.5 km = 50 km/h
Speed limit for 12.3 km = 80 km/h
Required: Time required to reach bus
Analysis: Find time to go first 8.5 km. Find time
to go last 12.3 km. Add times together,
and compare total with 20 min.
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be held responsible for content if any revisions, additions, or deletions are made to this page.

CHAPTER 4 ANSWER KEY
8.5 km
Solution: Time to go first 8.5 km =
50 km/h
Time to go first 8.5 km = 0.17 h
12.3 km
Time to go first 8.5 km =
80 km/h
Time to go first 8.5 km = 0.154 h
Total time = 0.17 h + 0.154 h
Total time = 0.324 h
60 min
Total time = 0.324 h ×
h
Total time = 19.44 min
20 min is greater than 19.44 min.
Paraphrase: If you are not slowed by traffic and you
do not hit any red lights, you will get to
the bus in time.
BLM 4-5, Energy and Work Practice
Problems/Skill Builder
Goal: Students practise solving problems that involve
work.
Answers
1. 1.2 × 10 2 J
2. 2.33 × 10 6 J
3. (a) 4.4 × 10 3 J
(b) None. The direction of the force was
perpendicular to the direction of the motion.
4. 2.330 m
5. 2.50 × 10 2 m
6. 0.16 m
7. 1.3 × 10 3 N
8. (a) 3.9 × 10 3 J
(b) 1.8 m
BLM 4-6, Graphical Methods for
Determining Work/Skill Builder
Goal: Students determine work done using force versus
position graphs.
Answers
1. (a) 42 J
(b) 17.5 J
(c) 40 J
2. (a) approximately 77.5 J
(b) approximately 253 J
BLM 4-7, Fuelled by Farm Waste/Science
Inquiry
Goal: Students expand their knowledge of methods that
are being developed to conserve energy while protecting
the environment.
Answers
Essays will vary significantly. The essays should resemble
the examples given in the BLM.
BLM 4-8, Chapter 4 Test/Assessment
Goal: Students demonstrate their understanding of the
information presented in Chapter 4.
Answers
1. F: James Watt improved the design of the
Newcomen steam engine.
2. F: Modern scientists accept the kinetic-molecular
theory of heat.
3. T
4. F: Temperature is a measure of the average kinetic
energy of the atoms and molecules in an object.
5. T
6. (d)
7. (a)
8. (e)
9. (b)
10. (c)
11. turbine
12. area under the curve
13. internal combustion
14. kinetic-molecular
15. less than
16. (d)
17. (b)
18. (d)
19. (a)
20. (b)
21. (b)
22. (d)
23. (a)
24. (c)
25. (a)
26. 1 . 2 3
27. 1 . 1 0 2
28. 2 . 3 4 3
29. James Joule hung a weight on a string over a pulley.
The string was wrapped around an axle, which was
attached to a paddle wheel. The paddle wheel was
immersed in water. When the weight fell, it turned the
paddle wheel in the water. James Joule measured the
distance that the weight fell and the increase in the
temperature of the water. He related the loss in
gravitational potential energy of the weight to the gain
in the temperature of the water. He calculated the
amount of mechanical energy that was transformed
into heat in the water.
Copyright © 2004 McGraw-Hill Ryerson Limited. Permission to edit and reproduce this page is granted to the purchaser for use in her/his classroom. McGraw-Hill Ryerson shall not
be held responsible for content if any revisions, additions, or deletions are made to this page.