Work and Energy Concepts

These flashcards cover key concepts around work, energy, and the calculations associated with them.

What does it mean if a force is said to do 'work'?

It means the force causes an object to be displaced through a distance.

What is the equation used to calculate work done?

Work done = Force x Distance.

What are the appropriate units for work done, force, and distance?

Work done is in Joules, force is in Newtons, and distance is in metres.

What distance must be used when calculating work done?

The distance that is moved along the line of action of the force.

Under what circumstance is 1 joule of work done?

When a force of 1 Newton causes a displacement of 1 metre.

How much work is done by a force of 10N over a distance of 5m?

50 Joules.

What is the calculation for work done with a force of 10N over a distance of 5m?

Work done = 10N x 5m = 50 J.

What happens when work is done against frictional forces?

A rise in temperature of the object occurs and kinetic energy is converted to heat.

Why does air resistance slow down a projectile?

The object does work against the air resistance and kinetic energy is converted into heat.

What is the formula to calculate work done?

Work done = Force x Distance.

What is the unit of measurement for work?

Joules.

In what scenario is work done equal to 0?

When there is no displacement or the force is perpendicular to the displacement.

What happens to kinetic energy when work is done against air resistance?

Kinetic energy is converted into heat.

What is the relationship between force, distance, and work?

Work is the product of force and the distance moved in the direction of that force.

What is meant by 'line of action' of the force?

It refers to the direction in which the force is applied.

How does one joule of work relate to forces and distance?

One joule of work is done when a force of 1 Newton moves an object 1 metre.

What kind of energy transformation occurs when work is done against friction?

The mechanical energy is transformed into thermal energy.

How does friction affect the efficiency of work done?

Friction reduces the efficiency because some energy is lost as heat.

Can work be done if the object doesn't move?

No, work requires displacement in the direction of the force.

What is the result of work done against a resistance like air?

The object loses kinetic energy, slowing it down.