Year 7 Science · Unit 3 · Lesson 8

Pressure — Qualitative

Challenge Worksheet

Name

Date

Class

Learning Goals

Evaluate a generalised claim about pressure by finding counterexamples.
Recognise that high pressure is sometimes desirable and explain why using scientific reasoning.
Distinguish between contexts where reducing pressure is the goal and where concentrating it is the goal.

Go Deeper

Evaluate the claim

Someone claims...

"A flat-soled boot is always safer and better than a pointed heel in all situations. Wide, flat surfaces reduce pressure, which prevents damage and injury — so engineers and designers should always aim to spread forces over the largest possible area. Pointed or sharp surfaces are always the dangerous option and should be avoided wherever possible."

(a) What part of this claim is supported by the science you have learned about pressure? Give one specific example from the lesson that supports the claim.

Challenge 2 marks

(b) What is misleading or incomplete about this claim? Give at least TWO counterexamples — situations where a small contact area (high pressure) is actually useful or necessary. Explain why high pressure is beneficial in each case.

Challenge 3 marks

(c) Rewrite the claim to make it more accurate and complete. Your improved version should include the idea that whether high or low pressure is better depends on the purpose of the design.

Challenge 2 marks

Show What You Know

1. A surgeon uses a very sharp, thin scalpel blade to make a precise cut in tissue. A nurse applies a wide adhesive bandage to protect the wound. Explain how both the surgeon's scalpel and the bandage are examples of pressure principles in action — even though one creates very high pressure and the other creates very low pressure. Why is each the correct tool for its job?

Challenge 3 marks

2. Red kangaroos have large, flat hind feet that absorb impact pressure when landing from large jumps. Design a different animal adaptation (real or imagined) that uses pressure principles to help an animal survive. Describe what body structure it would have, what problem it solves, and how pressure science explains it.

Challenge 4 marks

Wrap Up

In one sentence, what was the main idea of this lesson?