Question

5 place the materials in order according to how quickly sound waves travel through them.
warm air
cold air
steel
water
1 (fastest)
2
3
4 (slowest)

Explanation:

Step1: Recall sound speed in media

Sound travels fastest in solids, then liquids, then gases. Also, in gases, warmer air has faster sound speed than colder air (since warmer air molecules move faster).

Step2: Classify materials

• Steel (solid) → fastest among these.
• Water (liquid) → next.
• Warm air and Cold air (gases). Warm air has higher speed than cold air, so warm air is faster than cold air.

Step3: Order from fastest to slowest

1. Steel (solid, fastest in these)
2. Water (liquid)
3. Warm air (gas, faster than cold air)
4. Cold air (gas, slowest)

Answer:

1 (fastest): Steel
2: Water
3: Warm air
4 (slowest): Cold air