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In physics, work is defined as
In physics, work is defined as
force times distance
If you lift two loads up one story, how much work do you do compared to lifting just one load up one story?
If you lift two loads up one story, how much work do you do compared to lifting just one load up one story?
If you lift one load up two stories, how much work do you do compared to lifting one load up only one story?
If you lift one load up two stories, how much work do you do compared to lifting one load up only one story?
If Nellie Newton pushes an object with twice the force for twice the distance, she does
If Nellie Newton pushes an object with twice the force for twice the distance, she does
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The unit of work is the
The unit of work is the
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Power is defined as the
Power is defined as the
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The unit of power is the
The unit of power is the
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Potential energy is the energy an object has because of its
Potential energy is the energy an object has because of its
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The amount of potential energy possessed by an elevated object is equal to
The amount of potential energy possessed by an elevated object is equal to
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Kinetic energy of an object is equal to
Kinetic energy of an object is equal to
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How much farther will a car traveling at 100 km/s skid than the same car traveling at 50 km/s?
How much farther will a car traveling at 100 km/s skid than the same car traveling at 50 km/s?
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An arrow in a bow has 70 J of potential energy. Assuming no loss of energy to heat, how much kinetic energy will it have after it has been shot?
An arrow in a bow has 70 J of potential energy. Assuming no loss of energy to heat, how much kinetic energy will it have after it has been shot?
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Energy is changed from one form to another with no net loss or gain.
Energy is changed from one form to another with no net loss or gain.
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As a pendulum swings back and forth
As a pendulum swings back and forth
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When a car's speed triples, its kinetic energy
When a car's speed triples, its kinetic energy
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Rockets are launched from an airplane in the forward direction of motion. The kinetic energy of the airplane will be
Rockets are launched from an airplane in the forward direction of motion. The kinetic energy of the airplane will be
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A job is done slowly, and an identical job is done quickly. Both jobs require the same amount of work but different amounts of
A job is done slowly, and an identical job is done quickly. Both jobs require the same amount of work but different amounts of
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Which requires more work: lifting a 70-kg sack vertically 2 meters or lifting a 35-kg sack vertically 4 meters?
Which requires more work: lifting a 70-kg sack vertically 2 meters or lifting a 35-kg sack vertically 4 meters?
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A ball is thrown into the air with 100 J of kinetic energy which is transformed to gravitational potential energy at the top of its trajectory. When it returns to its original level after encountering air resistance, its kinetic energy is
A ball is thrown into the air with 100 J of kinetic energy which is transformed to gravitational potential energy at the top of its trajectory. When it returns to its original level after encountering air resistance, its kinetic energy is
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An object that has kinetic energy must be
An object that has kinetic energy must be
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An object that has kinetic energy must have
An object that has kinetic energy must have
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Which has greater kinetic energy, a car traveling at 30 km/h or a half-as-massive car traveling at 60 km/h?
Which has greater kinetic energy, a car traveling at 30 km/h or a half-as-massive car traveling at 60 km/h?
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A person on a roof throws one ball downward and an identical ball upward at the same speed. The ball thrown downward hits the ground with 140 J of kinetic energy. Ignoring air friction, with how much kinetic energy does the second ball hit the ground?
A person on a roof throws one ball downward and an identical ball upward at the same speed. The ball thrown downward hits the ground with 140 J of kinetic energy. Ignoring air friction, with how much kinetic energy does the second ball hit the ground?
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An object at rest may have
An object at rest may have
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If an object has kinetic energy, then it also must have
If an object has kinetic energy, then it also must have
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If the velocity of a moving object doubles, then what else doubles?
If the velocity of a moving object doubles, then what else doubles?
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All simple machines ideally work on the principle that
All simple machines ideally work on the principle that
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About how efficient is a typical gasoline-burning car engine?
About how efficient is a typical gasoline-burning car engine?
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A small economy car (low mass) and a limousine (high mass) are pushed from rest across a parking lot, equal to distances with equal forces. The car that receives more kinetic energy is the
A small economy car (low mass) and a limousine (high mass) are pushed from rest across a parking lot, equal to distances with equal forces. The car that receives more kinetic energy is the
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A popular toy consists of an aligned row of identical elastic balls suspended by strings so they touch each other. When two balls on one end are elevated and released, they slam into the array of balls and two balls pop out the other side. If instead, one ball popped out with twice the speed, this would be a violation of the conservation of
A popular toy consists of an aligned row of identical elastic balls suspended by strings so they touch each other. When two balls on one end are elevated and released, they slam into the array of balls and two balls pop out the other side. If instead, one ball popped out with twice the speed, this would be a violation of the conservation of
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Consider molecules of hydrogen gas and molecules of heavier oxygen gas that have the same kinetic energy. The molecules with the greater speed are
Consider molecules of hydrogen gas and molecules of heavier oxygen gas that have the same kinetic energy. The molecules with the greater speed are
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Study Notes
Work and Energy Concepts
- Work is defined as force multiplied by distance.
- Lifting two loads to one story requires twice the work compared to lifting one load.
- Lifting one load up two stories requires twice the work compared to lifting it one story.
- Applying twice the force over twice the distance results in four times the work done.
Units of Measurement
- The standard unit of work is the joule (J).
- Power is defined as the work done divided by the time taken, with the unit of power being the watt (W).
Types of Energy
- Potential energy is the energy due to an object's location.
- The potential energy of an elevated object equals the work done in raising it.
- Kinetic energy is calculated as one-half the mass of an object multiplied by the square of its speed.
Kinetic Energy and Motion
- A car traveling at 100 km/s will skid four times farther than the same car at 50 km/s.
- When an arrow in a bow has 70 joules of potential energy, it will have 70 joules of kinetic energy after being shot, assuming no energy loss.
- Energy conversion occurs without net loss or gain, remaining consistent.
Mechanical Energy Relationships
- As a pendulum swings, potential and kinetic energy interchange.
- When the speed of a car triples, its kinetic energy increases by nine times.
- Launching rockets from an airplane decreases the airplane's kinetic energy.
Work Comparison
- Lifting a 70 kg sack 2 meters and a 35 kg sack 4 meters requires the same amount of work.
- A ball thrown upward and one thrown downward from the same height will both have equal kinetic energy when hitting the ground under ideal conditions (neglecting air resistance).
Momentum and Kinetic Energy
- An object in motion possesses kinetic energy and must also have momentum.
- If the velocity of a moving object doubles, its momentum doubles as well.
Efficiency and Simple Machines
- Ideal simple machines operate on the principle that work input equals work output.
- A typical gasoline-powered car engine operates at approximately 30% efficiency.
Comparisons of Kinetic Energy
- A small economy car and a large limousine pushed with equal forces and over equal distances will both receive the same amount of kinetic energy.
- In a collision of elastic balls, if one exits with double the speed, it would violate the conservation of energy.
Molecular Speed Relations
- For molecules of equal kinetic energy, lighter hydrogen molecules have greater speeds than heavier oxygen molecules.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge of key concepts from Physics Chapter 9 with these flashcards. Each card presents a term or question followed by its definition or answer to help reinforce your understanding of work and energy. Ideal for review and studying key physics principles.
