Explain means give the reason
The most common way to lose explain marks is to describe instead. Saying "the ball speeds up" describes; saying "the resultant force acts downward, so by Newton's second law the ball accelerates" explains. The examiner is looking for the mechanism, not the observation.
Build a cause-and-effect chain
Strong explanations read as a chain of linked statements:
- Name the quantity involved and how it changes.
- State the physics rule that connects it to the next quantity.
- Give the result, then continue the chain if the question has more steps.
Words like because, so, therefore and as a result show the links clearly and are worth using deliberately.
Use precise physics language
Replace vague words with named quantities. "It gets pushed" is weaker than "the pressure difference produces an upward force." Name forces, directions, and the law or principle, such as conservation of momentum or the principle of moments. Precision is what earns each mark.
Match the number of points to the marks
A four-mark explain question usually needs four distinct linked ideas, not one idea repeated. Before moving on, count the separate points in your chain against the marks available and add the missing link if you are short.
Practise turning description into explanation
Take your own answers to past explain questions and underline where you only described. Rewrite those into a cause-and-effect chain with named quantities and a law. Doing this a few times reshapes how you answer, and a one-to-one review of your explanations can catch links you keep leaving out.