Which of the following best represents the energy transformations in a coal-fired electric power plant?

chemical ==> thermal ==> kinetic ==> electromagnetic

1. Which laws of physics, if any, distinguish between the backward and the forward direction in time?

The second law of thermodynamics but not the law of conservation of energy.

1. When water evaporates from the ocean and rises into the atmosphere, the energy transformation is

radiant energy ==> gravitational energy

Which of the following is not a heat engine?

hydro-electric generating plant

In the operation of a steam-electric generating plant, the work output [from thermal energy to work] occurs

at the point where the hot steam pushes against the turbine

The "energy efficiency" of a device is

its useful energy output divided by the total energy put into the device.

There are no known exceptions to

the law of conservation of energy

To get out of bed with the least amount of work, should your bed be on the floor, or at a meter high?

meter high; less work needs to be done lifting yourself to your feet

Which of the following is an "irreversible" process?

perfectly elastic ball that falls, rebounds from floor and back orig height

According to the second law of thermodynamics,

work cannot entirely be converted into thermal energy

"Hybrid drive" automobiles use

a small gasoline engine that drives an electric generator

1. Which type of generating plant would you expect to be more energy efficient, steam-electric or hydroelectric?

Hydroelectric, as it is not a heat engine, restricted by 2nd law of thermo

When you touch a piece of ice,

thermal energy flows from your hand to the ice

What is the direction of energy flow for a fridge? Is is a spontaneous action, or is outside assistance required?

cold=>hot; assistance needed, as this is against how thermal energy flows

The "efficiency" of a heat engine is defined to be

work output divided by thermal energy input

According to the second law of thermodynamics,

thermal energy flows spontaneously from high temperatures=>low temperatures

1. A physics professor pushes against a stationary wall, sweating. Is he doing any actual physical work on the wall?

No, because the force of his hands=force of the wall pushing back.

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Physics Exam 2 Review (Day One)

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PHY 110 Review Quiz for Exam #2, Day One

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Questions 38

Answers

1
A fundamental physical reason for the bicycle's high efficiency as a transportation device is
both of the above
it is not a heat engine
it is a wheeled vehicle
it is a heat engine, but one that doesn't burn fossil fuels
2
Which of the following is one of the drawbacks of the automobile engine?
low efficiency
CO is injected into the atmosphere
CO2 is injected into the atmosphere
all of the above
3
The type of energy that a swinging pendulum has at the high point of its swing is
thermal
kinetic
elastic
gravitational
4
Which of the following best represents the energy transformations in a coal-fired electric power plant?
gravitational ==> kinetic ==> electromagnetic
electromagnetic ==> thermal ==> kinetic.
chemical ==> thermal ==> kinetic ==> electromagnetic
radiant ==> kinetic ==> electromagnetic ==> thermal
5
1. Which laws of physics, if any, distinguish between the backward and the forward direction in time?
The law of conservation of energy and the second law of thermodynamics
The second law of thermodynamics but not the law of conservation of energy.
The law of conservation of energy but not the second law of thermodynamics
none
6
1. When water evaporates from the ocean and rises into the atmosphere, the energy transformation is
radiant energy ==> gravitational energy
kinetic energy ==> thermal energy
chemical energy ==> thermal energy
gravitational energy ==> electromagnetic energy
7
Which of the following is not a heat engine?
nuclear electric power plant
hydro-electric generating plant
coal-fired electric generating plant
automobile engine
8
In the operation of a steam-electric generating plant, the work output [from thermal energy to work] occurs
the point where the energy from the furnace is transferred into the boiler
in the condenser
in the electric generators
at the point where the hot steam pushes against the turbine
9
The temperature of a nice day out is
25 degrees C
0 degrees C
10 degrees C
50 degrees C
10
In order to quadruple an object's kinetic energy, we must
double its speed
quadruple its height
double its height
quadruple its speed
11
The "energy efficiency" of a device is
its total energy output divided by the total energy put into the device.
its useful energy output divided by the total energy put into the device.
the total energy put into the device divided by its thermal energy output.
its thermal energy output divided by the total energy put into the device.
12
There are no known exceptions to
the law of conservation of energy
Newton's law of motion
both of the above
Nonsense--all physical principles have known exceptions.
13
Chemical energy is transformed into gravitational energy when
a block slides downhill
a leaf undergoes photosynthesis
a car accelerates
a person walks uphill
14
To get out of bed with the least amount of work, should your bed be on the floor, or at a meter high?
meter high; less work needs to be done lifting yourself to your feet
on the floor; less work is done getting your feet to the floor
makes no difference; the physical work done is zero
makes no difference; you must change your position regardless
15
Which of the following is an "irreversible" process?
none of the above
a block of wood sliding to a stop along a tabletop
perfectly elastic ball that falls, rebounds from floor and back orig height
both of the above
16
“Energy” could best be defined as
stored momentum
the ability to do work
matter in motion
the amount of force a system is capable of exerting
17
According to the second law of thermodynamics,
the entropy of all the participants in any physical process cannot increase
energy in must equal energy out
the entropy of all the participants in any physical process cannot decrease
work cannot entirely be converted into thermal energy
18
"Hybrid drive" automobiles use
large batteries recharged by plugging them into the wall socket
H fuel that burns much like gasoline w/in an engine, driving the wheels
small batteries energizing a small gasoline engine that drives the wheels
a small gasoline engine that drives an electric generator
19
1. Which type of generating plant would you expect to be more energy efficient, steam-electric or hydroelectric?
Steam-electric, as it can have a very high operating temp. due to boiler
Hydroelectric, as it is not a heat engine, restricted by 2nd law of thermo
Hydroelectric, as there is greater energy in a lake raised behind a dam
Steam-electric, as there is more energy/ton fossil fuels than H2O in a dam
20
The amount of energy consumed in one day in your home town could be measured in units of
newtons
joules
horsepower
watts
21
When you touch a piece of ice,
work flows from your hand to the ice
thermal energy flows from your hand to the ice
chemical energy flows from the ice to your hand
work flows from the ice to your hand
22
What is the direction of energy flow for a fridge? Is is a spontaneous action, or is outside assistance required?
hot=>cold; assistance needed, as this is against how thermal energy flows
cold=>hot; assistance needed, as this is against how thermal energy flows
cold=>hot; no assistance needed, as this is how thermal energy flows
hot=>cold; no assistance needed, as this is how thermal energy flows
23
Thermal energy can be described as
microscopic kinetic energy
macroscopic kinetic energy
both of the above
none of the above
24
According to the second law of thermodynamics,
energy process that uses thermal energy to do work must have exhaust
) thermal energy flows spontaneously from hot objects to cold objects
total entropy cannot decrease in a system by any participants
all of the above
25
The "efficiency" of a heat engine is defined to be
work output divided by thermal energy input
work output divided by thermal energy output
thermal energy output divided by thermal energy input
thermal energy output divided by work input
26
Entropy is best defined as
energy that is due to chemical structure
microscopic organization
energy that is due to its temperature
microscopic disorganization
27
One joule is the same as one
m/s/s
watt-meter
newton-meter
newton-second
28
1. At 10 cents per kilowatt-hour, how much does it cost to run a 100 watt light bulb for 200 hours every month?
$2/month
$20/month
its impossible to determine without the knowing voltage
20 cents/month
29
According to the second law of thermodynamics,
thermal energy flows spontaneously from low temperatures=>high temperatures
energy in==energy out
work cannot be entirely converted into thermal energy
thermal energy flows spontaneously from high temperatures=>low temperatures
30
1. In one cycle of operation, the thermal energy input to a particular heat engine is 200 joules and the exhaust is
impossible to determine from the given information
40%
20%
60%
31
Which one of our 8 standard physical forms of energy is present in sunlight?
chemical
thermal
radiant
solar
32
1. A physics professor pushes against a stationary wall, sweating. Is he doing any actual physical work on the wall?
No, because the wall is not moving
Yes, he is exerting a force against the wall during a perdiod of time
No, because the force of his hands=force of the wall pushing back.
Yes, because his arm muscles are moving other muscles through a distance
33
What form(s) of energy does a falling rubber ball have when it is halfway down?
Kinetic, gravitational, and elastic
gravitational only
kinetic and gravitational
kinetic only
34
1. Elizabeth lifts a 10 N book from the floor to the table, a height of 2 m. The energy transformation is
gravitational ==> chemical
chemical ==> gravitational
electromagnetic ==> gravitational
thermal ==> gravitational
35
The type of energy that a swinging pendulum has at the low point of its swing is
thermal
gravitational
kinetic
elastic
36
At constant speed, you lift a book weighing 12 N from the floor to a shelf 2 m above the floor. What is the work done?
6 Joules
24 Joules
24 Watts
6 Watts
37
Which of the following is a unit of energy?
watt
calorie
newton/second
newton
38
Large curved cooling towers can often be seen at
steam-electric power plants
hydro-electric plants
nuclear power plants
both of the above

Physics Exam 2 Review (Day One) Flashcards | StudBud