AnswersDL Physical Science A switched content 2023Unit Test

Unit Test — Unit test Answers

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1
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Which shows the formula for converting from kelvins to degrees Celsius?

°
°C = (9/5 × K) +32
°
°C = 5/9 × (K – 32)
°
°C = K – 273
°
°C = K + 273
2
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Which phrase best describes a machine?

A
any device that makes work easier
B
any device that moves an object
C
any device that has multiple parts
D
any device that uses energy
3

Cindy pours cool milk into a hot bowl of oatmeal and then stirs it with a room-temperature spoon. Which substance will have heat flow from it to the other substances?

t
the milk
t
the spoon
t
the oatmeal
t
the surrounding air
4

Which compares the problems associated with radioactive waste created from generating electricity using fusion reactions to waste created from generating electricity using fission reactions?

A
The radioactive waste from fusion reactions becomes less hazardous much sooner than the waste from fission reactions.
B
The radioactive waste from fission reactions becomes less hazardous much sooner than the waste from fusion reactions.
C
Although their radioactive wastes are hazardous for the same period of time, fusion reactions produce less waste than fission reactions.
D
Although their radioactive wastes are hazardous for the same period of time, fission reactions produce less waste than fusion reactions.
5

The total energy in a system is 675 J. The kinetic energy changes from 296 J to 432 J. Which statement best describes the potential energy of this system?

A
It changes from 296 J to 432 J.
B
It changes from 379 J to 243 J.
C
It changes from 432 J to 296 J.
D
It changes from 243 J to 379 J.
6

Ryan is examining the energy of the particles in a bar of gold. What is Ryan most likely studying?

A
thermal energy
B
electric energy
C
potential energy
D
internal energy
7

Mateo’s parents are thinking about investing money to help develop a new fusion power plant. Which issue is most important to consider before making the investment?

A
Fusion has never been controlled, so how have they succeeded in doing it?
B
The fuel is quite limited, so have they discovered a more common fuel?
C
Fusion has been generating electricity for decades, so why build another fusion power plant?
D
Fusion requires high temperatures and pressures, so how have they reduced the energy cost for it?
8

A 4400 W motor is used to do work. If the motor is used for 200 s, how much work could it do? (Power: P = W/t)

A
22 J
B
4200 J
C
4600 J
D
880,000 J
9

Which will reduce the possible environmental damage associated with mining uranium?

A
installing newer water recycling systems in older power plants
B
increasing the reprocessing of used fuel for reuse
C
building additional fission nuclear power plants
D
developing better places to store radioactive wastes
10

A nuclear power plant is scheduled to undergo a retrofitting. What is the most likely outcome of the change?

A
The power plant will no longer generate radioactive wastes.
B
The power plant will recycle the water it uses to cool the reactor.
C
The power plant will be able to reprocess its used uranium fuel.
D
The power plant will switch from fission reactions to fusion reactions.
11

Under which condition is no work done?

A
A force pushes an object and slows it down.
B
A force pulls an object and speeds it up.
C
A force pulls down on an object that moves downward.
D
A force pushes up on an object that stays in place.
12

A machine has a mechanical advantage of 0.6. What force should be applied to the machine to make it apply 600 N to an object?

A
100 N
B
360 N
C
1000 N
D
3600 N
13

Which best describes a difference between energy transformations in power plants and dams?

A
Only power plants use fossil fuels to transform energy.
B
Only dams use fission to generate thermal energy.
C
Only power plants use water to turn turbines.
D
Only dams use mechanical energy to produce electricity.
14

Which best defines energy?

A
a type of wave that carries energy through space, where there is almost no matter
B
a disturbance that carries energy form one place to another through matter and space
C
the ability to do work
D
pressing to make more compact
15

Dimas reads that it takes 270 N to lift a firefighter’s equipment. If a firefighter does 5400 J of work carrying the equipment up a staircase, how high does the firefighter climb? (Work: W = Fd)

A
20 m
B
200 m
C
5130 m
D
1,458,000 m

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