The National 5 Physics exam is made up of two question papers. Paper 1 is a multiple choice paper. Paper 2 is made up of questions with several parts that need written answers.
Often these type of questions are the most challenging and can make a difference to gaining better grades. The key to writing a good answer is to recognise and be clear about what area of the course the question is based on. This involves a good and ready knowledge of
the course content based on effective revision.
Once clear on the question being asked, plan the structure of an answer by listing keywords which will help to gain marks.
Write a coherent and possibly concise answer with logical progression of what variable makes changes to others.
State or refer to any quantities that do not change.
Don’t use up/down arrows instead of the words increase or decrease in descriptions or explanations.
Sketch diagrams can be referred to as part of an answer.
For example, if a question asks you to: "Explain the increase in acceleration of a rocket as if takes off for the first kilometre of flight":
Consider what the physics is - Newton’s second law and unbalanced forces.
Keywords will include thrust, weight, mass, unbalanced force.
What is fixed - thrust.
What changes and the order making reference to any relationships as appropriate.
Suggested answer
"As the rocket climbs the thrust stays the same but the weight reduces as the mass of rocket fuel is burnt off. The unbalanced force (Thrust - Weight) increases and the mass of the rocket decreases so the acceleration of the rocket increases as \(a=F/m\)."
Note the gravitational field strength does not vary appreciably over the first km (weight only changes due to decrease in mass) so this would not be considered part of a correct answer.
