lesson
Energy moves between stores
1 · Learn
Energy can be stored in different ways, including kinetic, gravitational and chemical stores. Transfers can occur by forces doing work, electrically, by heating or by radiation. Energy is conserved overall, though some becomes spread through surroundings and less useful for the intended task.
A moving object slowing through friction does not destroy energy. Energy is transferred to thermal stores of the object and surroundings. Avoid saying energy is used up as though it ceases to exist.
2 · Worked example
A raised object falls: its gravitational store decreases while its kinetic store increases, with some transfer to surroundings if resistance acts.
3 · Your turn
When friction slows a sliding block, has its energy simply vanished?
Check your answer
No. Energy has been transferred, including to thermal stores of the block and surroundings.
4 · Apply your learning
Draw an energy account for a supplied simple process and include the surroundings rather than only the desired output.
Adult guidance and safety
Use supplied data and diagrams unless a qualified adult has approved the practical, equipment and risk assessment. No tasting substances, culturing unknown microbes, mains electricity, flames or hazardous chemical experiments at home. Models simplify reality; ask which assumptions affect the conclusion.
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Check a calculation · Year 5 onward
Use this only when your teacher or adult allows a calculator for the task. Show your thinking first. It does not replace mental or written arithmetic and does not mark your lesson answer.
Powers, roots and trigonometry · Year 7 onward
Use only when the task allows a calculator. Choose one operation at a time and record your working. Trigonometry here always uses degrees (DEG), not radians. Inverse sine, cosine and tangent return an angle, not a reciprocal. Keep exact fractions and π in answers when requested.
Approximate numerical results use up to 12 significant digits. Inverse sine returns −90° to 90°, inverse cosine 0° to 180°, and inverse tangent −90° to 90°; these are principal values, not every possible solution of a trigonometric equation.
My observation notebook
Follow your teacher's approved method and safety instructions. Record the sample or supplied dataset, conditions, measurements with units and uncertainties where appropriate. Distinguish observations from explanations. A described experiment is not permission to carry it out; do not improvise equipment or invent missing results.
Ask your teacher for support with the method and recording. A prediction is what you think might happen; an observation is what you actually see, hear or feel safely.
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