Questions: Choosing the Right Material for the Job

Question 1

You are designing a kitchen spatula. Why might you use metal for the flat part but rubber for the handle?

• A. Metal is cheaper and rubber is more colorful
• B. Metal is a good heat conductor and is rigid enough to flip food; rubber is an insulator that keeps the handle cool and provides a comfortable, non-slip grip
• C. Metal is lighter than rubber
• D. There is no good reason — both parts should be the same material

Answer: (B)

Different parts of the spatula do different jobs, so they need different properties. The flat part needs to be rigid and heat-resistant, which metal provides. The handle needs to stay cool (insulating) and be comfortable to grip (flexible, non-slip), which rubber provides. Using two materials gives you the best properties for each part.

Question 2

The most expensive material is typically the best choice for any job.

• T. True
• F. False

Answer: False

False. The best material is the one whose properties match the requirements of the job, regardless of price. A diamond window would be very hard, but glass does the job perfectly at a tiny fraction of the cost. A gold hammer would be too soft and heavy. Cost, weight, availability, and many other factors matter alongside the physical properties.

Question 3

What properties would you look for in a material to make an umbrella?

Model answer: Waterproof (non-absorbent) so rain slides off, lightweight so it is easy to carry, flexible enough to fold, and strong enough not to break in wind.

An umbrella needs several properties at once: it must repel water, be light, fold up, and withstand wind. No single property is enough — the designer must consider all the requirements together and find a material (usually a synthetic fabric like nylon) that satisfies them all.