Year 7 Science · Unit 3 · Lesson 14
Challenge Worksheet
Learning Goals
Design the investigation
Scenario
Your teacher gives you a bar magnet, a ruler, a single steel paper clip and a smooth bench. Your task is to design a fair test to answer the question: "At what distance does the magnet first start to move the paper clip?" You must plan it so that a classmate could repeat your method and get a similar result.
Write a clear method for your investigation. In your answer, state the variable you will change, two things you will keep the same, what you will measure, and one safety rule you will follow with the magnet. Then explain what result you predict and why, using the words "non-contact force" and "distance".
1. A student cuts a bar magnet exactly in half between its north and south poles, hoping to make one piece that is only north and one that is only south. Explain what really happens to each piece and why you can never get a single, separate pole.
2. Two students run the distance investigation but get different results for the same magnet. One did each distance only once; the other repeated each distance three times and took an average. Whose results are more reliable, and why? Suggest one more improvement to make the test fairer.
Wrap Up
In one sentence, what was the main idea of this lesson?