levo

Energy – Forces Doing Work

Changing a system's energy, and measuring work done

  • 3 things to know
  • Paper 2

Overview

The three ways a system's energy changes, by forces doing work, electrically and by heating, with examples of each, measuring work done with a newtonmeter and a distance, and work done as energy transferred in joules.

What you need to know

Answer each one before you reveal it.

Your recallNot started
Key term

Give an example of the energy of a system being changed in electrical equipment.

Key term

Give an example of the energy of a system being changed by heating.

Key term

State what must happen to a system for the energy stored in it to change.

Questions from this subtopic

Each one with the model answer underneath.

  1. 1

    Name the three ways in which the energy of a system can be changed.

    Model answer

    By work done by forces, electrically in equipment, and by heating.

  2. 2

    Give an example of the energy of a system being changed by work done by a force.

    Model answer

    Pushing a box along the floor transfers energy to the thermal stores of the box and the floor.

  3. 3

    Give an example of the energy of a system being changed in electrical equipment.

    Model answer

    The motor of a washing machine transfers energy electrically to the kinetic store of the drum.

  4. 4

    Give an example of the energy of a system being changed by heating.

    Model answer

    A gas flame under a pan transfers energy to the thermal store of the water inside it.

  5. 5

    Explain why pushing a car and switching on an electric heater are both described as changing the energy of a system.

    Model answer

    Both transfer energy into the system, one through a force doing work and the other by heating.

  6. 6

    State what must happen to a system for the energy stored in it to change.

    Model answer

    Energy must be transferred into or out of it by forces doing work, electrically, or by heating.

Other ways to work this

The same content, four other ways.

What is inside Levo

Six ways to work the same material.

1Closed book
2Open book
3Closed book

The 3-step method, run for you

Answer cold, learn it, then prove it stuck. Levo tracks the jump between your first attempt and your last.

Key Concepts of Physics
Motion and Forces
Conservation of Energy
Waves

Cram a whole paper in one sitting

Sort every topic into what you know and what you do not, then drill only the weak ones.

2.5 × = 9000 s.
360027001000

Blank Blitz makes facts automatic

Rapid timed gap-fills on the terms and numbers you need to recall without thinking.

ALength is measured in metres, with the symbol m.
BMass is measured in kilograms, symbol kg.
CTime is measured in seconds, symbol s.

Build It gets the exam shape right

Assemble a full-mark answer from its marking points, in the order an examiner wants them.

Watt means the unit of power, symbol W.
TrueFalse

Test It catches misconceptions

Spot the fault in a statement. The traps are the mistakes students actually make.

721941163128510

Brain Breaks between sessions

Short focus games to reset attention, so the next set lands better than the last.

Every question in Energy – Forces Doing Work, on a schedule.

Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.

Or £46 a year, about £3.83 a month. Cancel anytime.