levo

Work, Energy and Power

Kinetic and gravitational potential energy

  • 4 things to know
  • Papers 1 and 3

Overview

Recall questions on kinetic energy and gravitational potential energy, their equations, calculations and derivations from first principles, and the exchange between them for a freely falling object.

What you need to know

Answer each one before you reveal it.

Your recallNot started
Numbers

What is kinetic energy, how is it calculated, and how is the transfer of energy related to work done?

Numbers

When an object is lifted through a height h at constant velocity, what force is needed, how is the work done calculated, and what happens to that work?

Numbers

In deriving the kinetic energy equation from first principles, what two equations do you start with?

Key term

What is kinetic energy?

Questions from this subtopic

Each one with the model answer underneath.

  1. 1

    In deriving the kinetic energy equation from first principles, what two equations do you start with?

    Model answer

    W = Fx (definition of work done) and F = ma (Newton's second law).

  2. 2

    For an object accelerating from rest, how does the work done relate to kinetic energy in the derivation?

    Model answer

    When u = 0, the work done equals the kinetic energy gained: Eₖ = ½mv².

  3. 3

    What is kinetic energy?

    Model answer

    Kinetic energy is the energy an object possesses due to its motion.

  4. 4

    State the equation for calculating kinetic energy and define each term.

    Model answer

    Eₖ = ½mv², where m is mass and v is velocity.

  5. 5

    Calculate the kinetic energy when mass = 108.1 kg, velocity = 34.2 m/s.

    Model answer

    Kinetic energy = 0.5 × 108.1 × 34.2 × 34.2 = 63200 J.

  6. 6

    When deriving Eₖ = ½mv², how is the equation v² = u² + 2ax rearranged to express displacement?

    Model answer

    It is rearranged to give x = (v² − u²)/(2a).

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.

Practical Skills in the Written Papers
The Practical Endorsement
Physical Quantities and Units
Making Measurements and Analysing Data

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.

A wave.
longitudinaltransversestationary

Blank Blitz makes facts automatic

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

AForce is a vector quantity.
BDistance is a scalar quantity.
CVelocity is a vector quantity.

Build It gets the exam shape right

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

Density means mass per unit volume.
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 Work, Energy and Power, 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.