Work is done when an object is moved over a distance by a force applied in the direction of its displacement; the force is said to do work on the object.

When a ball is lifted to a height above the ground, what force does work on the ball, and over what distance?

The ball's weight does work on it, over a distance equal to the height it is lifted.

Work is done when a bird flies through the air because ______ does work against the bird.

Work is done when a bird flies through the air because air resistance does work against the bird.

True or False? A force of 500 N applied over a distance of 23 m does 11 500 J of work.

True. Work = 500 N × 23 m = 11 500 J .

One joule is equal to the work done by a force of one newton acting through a distance of one metre .

What is the relationship between work done and energy transferred?

Energy transferred (J) = work done (J) . Whenever work is done, energy is transferred from one store to another.

If a force acts in the same direction as an object's motion, what happens to the object's energy?

The object gains energy ; energy is transferred to its kinetic store.

If a force acts in the opposite direction to an object's motion, where is energy transferred?

Energy is transferred away to the thermal store of the object and its surroundings.

Changes in ______ are related to gravitational potential energy, while changes in speed are related to kinetic energy.

Changes in height are related to gravitational potential energy, while changes in speed are related to kinetic energy.

True or False? 1 J is equal to 1 N m.

True. Multiplying force (N) and distance (m) gives units of newton-metres, and 1 J = 1 N m .

Friction is a force that acts in opposition to the motion of an object, slowing it down.

How is energy transferred when friction acts on a moving object?

Energy is transferred by heating , raising the temperature of the object and its surroundings (their thermal stores).

What causes the rise in temperature when friction acts between two surfaces?

Imperfections at the interface between the object and the surface bump into and rub against each other; the work done against these frictional forces causes the temperature rise.

What type of force is air resistance, and how does it transfer energy to a moving object?

Air resistance is a type of friction ; energy is transferred by heating due to the work done against it as particles bump into the object.

Imperfections at the interface between an object and a surface ______ and rub up against each other, slowing the object down.

Imperfections at the interface between an object and a surface bump into and rub up against each other, slowing the object down.

True or False? Air resistance can cause an object to heat up as it moves through the atmosphere.

True. As the object moves, particles bump into it and work is done against the frictional force, transferring energy by heating .

GCSEPhysicsAQAFlashcardsForcesWork Done & Energy Transfer

Work Done & Energy Transfer (AQA GCSE Physics): Flashcards

Exam code: 8463

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FrontWork Done
Define work done.

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Cards in this collection (19)

Define work done.
Work is done when an object is moved over a distance by a force applied in the direction of its displacement; the force is said to do work on the object.
What happens if a force is applied to an object but no movement results?
No work is done.
When a ball is lifted to a height above the ground, what force does work on the ball, and over what distance?
The ball's weight does work on it, over a distance equal to the height it is lifted.
State the equation used to calculate work done, including the unit of each quantity.
$W = F s$
where W is work done in joules (J) or newton-metres (N m), F is force in newtons (N), and s is distance in metres (m).
Work is done when a bird flies through the air because ______ does work against the bird.
Work is done when a bird flies through the air because air resistance does work against the bird.
True or False?
A force of 500 N applied over a distance of 23 m does 11 500 J of work.
True.
Work = 500 N × 23 m = 11 500 J.
Define one joule.
One joule is equal to the work done by a force of one newton acting through a distance of one metre.
What is the relationship between work done and energy transferred?
Energy transferred (J) = work done (J). Whenever work is done, energy is transferred from one store to another.
If a force acts in the same direction as an object's motion, what happens to the object's energy?
The object gains energy; energy is transferred to its kinetic store.
If a force acts in the opposite direction to an object's motion, where is energy transferred?
Energy is transferred away to the thermal store of the object and its surroundings.
Changes in ______ are related to gravitational potential energy, while changes in speed are related to kinetic energy.
Changes in height are related to gravitational potential energy, while changes in speed are related to kinetic energy.
A woman lifts a 10 kg bucket 15 m out of a well (g = 9.8 N/kg). How much energy is transferred to the bucket?
$W = m \times g \times h = 10 \times 9.8 \times 15 = 1470 J$
This is the energy transferred to the bucket's gravitational potential store.
True or False?
1 J is equal to 1 N m.
True.
Multiplying force (N) and distance (m) gives units of newton-metres, and 1 J = 1 N m.
Define friction.
Friction is a force that acts in opposition to the motion of an object, slowing it down.
How is energy transferred when friction acts on a moving object?
Energy is transferred by heating, raising the temperature of the object and its surroundings (their thermal stores).
What causes the rise in temperature when friction acts between two surfaces?
Imperfections at the interface between the object and the surface bump into and rub against each other; the work done against these frictional forces causes the temperature rise.
What type of force is air resistance, and how does it transfer energy to a moving object?
Air resistance is a type of friction; energy is transferred by heating due to the work done against it as particles bump into the object.
Imperfections at the interface between an object and a surface ______ and rub up against each other, slowing the object down.
Imperfections at the interface between an object and a surface bump into and rub up against each other, slowing the object down.
True or False?
Air resistance can cause an object to heat up as it moves through the atmosphere.
True.
As the object moves, particles bump into it and work is done against the frictional force, transferring energy by heating.

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