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Questions and Answers
If the force acting on an object is plotted on the y-axis and the displacement of the object is plotted on the x-axis, what is the area under the curve of the resulting graph equal to?
If the force acting on an object is plotted on the y-axis and the displacement of the object is plotted on the x-axis, what is the area under the curve of the resulting graph equal to?
What kind of work is represented by the area below the x-axis in a force-displacement graph?
What kind of work is represented by the area below the x-axis in a force-displacement graph?
What quantity is represented by the x-axis in a force-displacement graph?
What quantity is represented by the x-axis in a force-displacement graph?
A force of 10 N acts on an object, causing it to move a distance of 5 m. What is the work done by the force if the angle between the force and displacement is 60°?
A force of 10 N acts on an object, causing it to move a distance of 5 m. What is the work done by the force if the angle between the force and displacement is 60°?
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A constant force of 20 N acts on an object, moving it 3 m. What is the work done by the force in this scenario?
A constant force of 20 N acts on an object, moving it 3 m. What is the work done by the force in this scenario?
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If the force acting on an object is constant and the object moves in the opposite direction of the force, what is the work done by the force?
If the force acting on an object is constant and the object moves in the opposite direction of the force, what is the work done by the force?
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A person lifts a 5 kg box vertically a distance of 2 m. What is the work done on the box by the person? (Assume g = 9.8 m/s²)
A person lifts a 5 kg box vertically a distance of 2 m. What is the work done on the box by the person? (Assume g = 9.8 m/s²)
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A car is traveling at a constant speed of 20 m/s. The engine does work on the car to overcome friction and air resistance. What is the net work done on the car?
A car is traveling at a constant speed of 20 m/s. The engine does work on the car to overcome friction and air resistance. What is the net work done on the car?
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What is the total work done on an object when it moves at constant velocity, assuming no other forces act on it?
What is the total work done on an object when it moves at constant velocity, assuming no other forces act on it?
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Which scenario does NOT involve work being done on the object?
Which scenario does NOT involve work being done on the object?
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When calculating the total work done on an object, what needs to be considered?
When calculating the total work done on an object, what needs to be considered?
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What happens to the total work when forces are acting in opposite directions on an object?
What happens to the total work when forces are acting in opposite directions on an object?
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If an object is moving in the direction of an applied force, what is the angle (u) between the force and displacement?
If an object is moving in the direction of an applied force, what is the angle (u) between the force and displacement?
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What type of work is done if a force is applied in the opposite direction of the object's displacement?
What type of work is done if a force is applied in the opposite direction of the object's displacement?
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In the context of lifting weights, which force opposes the applied force?
In the context of lifting weights, which force opposes the applied force?
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Which of the following statements about work done on an object is true?
Which of the following statements about work done on an object is true?
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What is the formula used to calculate work when a force varies during displacement?
What is the formula used to calculate work when a force varies during displacement?
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In the case of the tow truck pulling a car, what opposing force acts on the car?
In the case of the tow truck pulling a car, what opposing force acts on the car?
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When a child pulls a wagon at an angle, what affects the mechanical work done on the wagon most significantly?
When a child pulls a wagon at an angle, what affects the mechanical work done on the wagon most significantly?
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When pulling a box horizontally with a friction force acting on it, what must happen for mechanical work to be done?
When pulling a box horizontally with a friction force acting on it, what must happen for mechanical work to be done?
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If the normal force on an object is increased, how does that affect the work done on the object while moving horizontally?
If the normal force on an object is increased, how does that affect the work done on the object while moving horizontally?
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What does the equation W = Fd represent?
What does the equation W = Fd represent?
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In the context of weightlifting, what is the force being applied?
In the context of weightlifting, what is the force being applied?
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Why is work considered a scalar quantity, not a vector quantity?
Why is work considered a scalar quantity, not a vector quantity?
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What is the SI unit for work?
What is the SI unit for work?
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How does the equation W = Fd change when the force and displacement are not in the same direction?
How does the equation W = Fd change when the force and displacement are not in the same direction?
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What is the term for the type of work done when a force displaces an object in the direction of the force, as described in the text?
What is the term for the type of work done when a force displaces an object in the direction of the force, as described in the text?
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Which of the following is NOT a requirement for the equation W = Fd to be accurate?
Which of the following is NOT a requirement for the equation W = Fd to be accurate?
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What makes weightlifting an example of mechanical work?
What makes weightlifting an example of mechanical work?
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What is the work done by the force of friction when a box moves with constant velocity over a displacement of 12 m?
What is the work done by the force of friction when a box moves with constant velocity over a displacement of 12 m?
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What is the tension in the rope when the box is being pulled at constant velocity?
What is the tension in the rope when the box is being pulled at constant velocity?
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If a 62 kg person is in an elevator moving up at a constant speed of 4.0 m/s, what is the work done by the normal force during a 5.0 s ride?
If a 62 kg person is in an elevator moving up at a constant speed of 4.0 m/s, what is the work done by the normal force during a 5.0 s ride?
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What would happen to the work done by gravity if the elevator were to move down at a constant speed of 4.0 m/s for 5.0 s?
What would happen to the work done by gravity if the elevator were to move down at a constant speed of 4.0 m/s for 5.0 s?
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In the context of a cart being pulled horizontally with a force sensor, if the applied force and the displacement are parallel, what does this imply about the work done?
In the context of a cart being pulled horizontally with a force sensor, if the applied force and the displacement are parallel, what does this imply about the work done?
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Why must the work done in section C of the cart's movement be negative?
Why must the work done in section C of the cart's movement be negative?
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How much work would be done on a cart if a force sensor pulls it horizontally from rest to a displacement of 0.5 m with an applied force of 20 N?
How much work would be done on a cart if a force sensor pulls it horizontally from rest to a displacement of 0.5 m with an applied force of 20 N?
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What is the consequence of an object moving at constant velocity on a rough floor concerning the forces acting on it?
What is the consequence of an object moving at constant velocity on a rough floor concerning the forces acting on it?
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A person pushing a lawnmower exerts a force of 125 N at an angle of 40.0° below the horizontal. If the person pushes the lawnmower for a distance of 12.0 m, what is the mechanical work done by the person on the lawnmower?
A person pushing a lawnmower exerts a force of 125 N at an angle of 40.0° below the horizontal. If the person pushes the lawnmower for a distance of 12.0 m, what is the mechanical work done by the person on the lawnmower?
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A person pushing a lawnmower does mechanical work on the lawnmower. What is the relationship between the force applied by the person and the direction of motion of the lawnmower for work to be done?
A person pushing a lawnmower does mechanical work on the lawnmower. What is the relationship between the force applied by the person and the direction of motion of the lawnmower for work to be done?
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A person pushes a lawnmower with a force of 100 N, but the lawnmower does not move. How much work is done by the person on the lawnmower?
A person pushes a lawnmower with a force of 100 N, but the lawnmower does not move. How much work is done by the person on the lawnmower?
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A custodian pushes a vacuum cleaner with a force of 50 N at an angle of 30° to the horizontal. He pushes the vacuum cleaner for a distance of 3 m. What is the work done by the custodian on the vacuum cleaner?
A custodian pushes a vacuum cleaner with a force of 50 N at an angle of 30° to the horizontal. He pushes the vacuum cleaner for a distance of 3 m. What is the work done by the custodian on the vacuum cleaner?
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A student lifts a book from the floor to a shelf that is 1.5 meters above the floor. The book has a mass of 2 kg. How much work is done by the student on the book?
A student lifts a book from the floor to a shelf that is 1.5 meters above the floor. The book has a mass of 2 kg. How much work is done by the student on the book?
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A person carries a heavy box across a room, walking at a constant velocity. Does the person do work on the box?
A person carries a heavy box across a room, walking at a constant velocity. Does the person do work on the box?
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A car travels at a constant speed of 20 m/s for 10 seconds. How much work is done by the car's engine?
A car travels at a constant speed of 20 m/s for 10 seconds. How much work is done by the car's engine?
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A student pushes a box across a frictionless surface. What is the relationship between the work done by the student and the kinetic energy of the box?
A student pushes a box across a frictionless surface. What is the relationship between the work done by the student and the kinetic energy of the box?
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Study Notes
Work
- Work is done when a force causes a displacement in the direction of the force, or a component of the force.
- The equation for work done by a constant force is: W = F∆d, where W is work, F is force, and ∆d is displacement.
- The SI unit for work is the joule (J).
- Work is a scalar quantity, meaning it has magnitude only, not direction.
Constant Force and Displacement
- If force and displacement are in the same direction, the whole force contributes to the work done.
- If force and displacement are not in the same direction, only the component of the force in the direction of the displacement contributes to the work.
- The equation for this is W = F(cos θ)∆d, where θ is the angle between force and displacement.
Work Done by a Changing Force
- When the force varies, the work done is calculated by finding the area under the force-displacement graph.
- Average force in this case is used to calculate work: W = Favg∆d.
Positive and Negative Work
- Positive work occurs when the force and displacement are in the same direction.
- Negative work occurs when the force and displacement are in opposite directions.
- For example, friction will do negative work if it opposes an object's motion (think pushing a box across a rough floor).
- The total work done by multiple forces is the scalar sum of the work done by the individual forces.
No Work Done
- No work is done when the force applied is perpendicular to the displacement.
- Example: holding a heavy object still.
- Or when there is no displacement: static objects.
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Description
This quiz covers the fundamental concepts of work, including calculations involving constant and varying forces. Understand the relationship between force and displacement, and learn how to determine positive and negative work. Perfect for students seeking to solidify their grasp of physical principles.
