Grade 8 Objective 4

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Grade 8Objective 4
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1 The graph shows the movement
of a car over time. What is the cars average
speed? F 10 kilometers per hour G 15
kilometers per hour H 30 kilometers per
hour J 60 kilometers per hour
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2 Which of the following devices converts
chemical energy to light energy? A C
Wind turbines
Flashlight B D
Electric Lamp Solar cells
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3 Diesel fuel is used in the engines of the
machines and trucks at the quarry. Which of
these is the main energy transformation as the
fuel is used by the engines? F Electrical
energy is converted to heat energy. G Heat
energy is converted to potential energy. H
Electrical energy is converted to kinetic
energy. J Chemical energy is converted to
kinetic energy.
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4 Which energy transformation occurs when a
match is lit? F Chemical energy to heat
energy G Heat energy to potential energy H
Electrical energy to heat energy J Kinetic
energy to potential energy
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5 The picture shows a lima bean
seedling as the root starts to grow into the
soil. The root tip is able to push through the
soil because it acts as a A wheel B
pulley C gear D wedge
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6 When the human heart contracts, it pumps
blood to other parts of the body. When the
heart contracts, the blood moves because the
A pressure in the heart increases B
temperature of the blood increases C
density of the blood increases D size of
the heart increases
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7 The diagram above shows a barrel
moving toward a waterfall. The barrel will have
the greatest potential energy at which of these
locations? A W B X C Y D Z
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8 Which of the following best represents stored
potential energy? F Air leaking from a flat
tire G Stress built up in a rock fault H
Heat given off by a forest fire J Water
flowing through a hose
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9 At which point on the roller
coaster will the car have the greatest amount
of kinetic energy? F W G X H Y J Z
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10 If a force is applied for 15 seconds,
in which situation will the box be moved the
greatest distance?
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Javelina
11 Javelinas need strong leg muscles to help
provide enough force for them to accelerate to
high speeds. This fast movement can
help javelinas escape from predators and reach
the safety of the pack. If a javelina runs 42 m
in 6 s, what is its average speed? A 6
m/s B 7 m/s C 48 m/s D 252 m/s
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12 All of these could cause disruptions in
the reception of radio waves EXCEPT F
cloud cover G lightning bolts H rain J
visible light
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13 In the diagram above, at which
point are the sound waves being generated? A
R B S C T D V
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Grade 8 Objective 4 Answer Key
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