Teaching the Kid: Middle School Wave Worksheet | Middle school ... - Free Printable

Let’s go step by step to solve each question on the worksheet.

---

Part 1: Labeling the Wave Diagram (A–F)

Looking at the wave diagram:

- A points to the very top of a wave → that’s the crest
- B is the horizontal distance from one crest to the next → that’s the wavelength
- C is the vertical height from the middle line to the crest → that’s the amplitude
- D points to the bottom of the wave → that’s the trough
- E is the horizontal distance from one trough to the next → also part of the wavelength (same as B)
- F is the vertical distance from the middle line down to the trough → also part of the amplitude (same as C, but downward)

So:

A: Crest
B: Wavelength
C: Amplitude
D: Trough
E: Wavelength
F: Amplitude

*(Note: Sometimes amplitude is defined as the full peak-to-trough distance, but in most school worksheets like this, it’s measured from rest position to crest or trough — so both C and F are amplitude.)*

---

Part 2: Frequency Questions (Wave 1, 2, 3)

We’re shown three waves made of dots. We need to count how many complete wavelengths are in each.

Remember: One wavelength = from crest to crest (or trough to trough), or any repeating point to the same point again.

Wave 1:
Look at the pattern. It goes up-down-up-down... Let’s count full cycles.
From start to end, we can see:
- First crest → first trough → second crest → second trough → third crest → third trough → fourth crest? Wait, let’s be careful.

Actually, looking closely:

Wave 1 has 3 full “humps” going up and down. Each hump (up and down) is half a wavelength? No — actually, one full wave = one crest + one trough.

In Wave 1:
Starts at middle → goes up (crest) → down (trough) → up (crest) → down (trough) → up (crest) → down (trough) → ends at middle.

That’s 3 full cycles (each cycle = crest + trough). So:

→ Wave 1 = 3 wavelengths

Wait — let me double-check with spacing.

If you look at the dotted lines, they mark the peaks and valleys. From first peak to second peak = 1 wavelength. In Wave 1, there are 3 peaks? Actually, counting the number of times it completes a full oscillation.

Better way: Count how many times it crosses the center line going upward (that’s one per wavelength).

But simpler: Look at the shape.

Wave 1: Starts at zero, goes up, down, up, down, up, down, back to zero → that’s 3 full waves.

Yes → Answer for Q1: 3

Wave 2:
Same length horizontally, but more squished. More waves fit in the same space.

Count: Up, down, up, down, up, down, up, down → that’s 4 full waves? Let’s see:

Starts at zero → up → down → up → down → up → down → up → down → ends at zero? That would be 4 full cycles.

Actually, looking at the dots: There are 4 crests and 4 troughs → so 4 full wavelengths.

→ Answer for Q2: 4

Wave 3:
Very stretched out. Only one big bump.

Starts at zero → slowly up → slowly down → back to zero → that’s only HALF a wave? Wait no.

Actually, it goes up to a crest, then down to a trough, then back toward zero — but doesn’t complete the second half? Let’s check.

Looking carefully: It starts at left, rises to a peak, falls to a valley, and returns to the center line at the right edge. That’s exactly ONE full wave (crest + trough).

Wait — if it starts at equilibrium, goes to crest, to trough, back to equilibrium — that’s one full cycle.

Yes → Wave 3 = 1 wavelength

But wait — some might say it’s less? Let me visualize again.

Actually, in many such diagrams, if it shows one complete "S" shape (up and down once), that’s one wavelength.

Looking at Wave 3: It has one clear crest and one clear trough, and returns to baseline → yes, 1 full wavelength.

→ Answer for Q3: 1

Now:

Q4: Which wave has the highest frequency?

Frequency = how many waves pass a point per second. If all waves are drawn over the same time period (which they are — same horizontal length), then the wave with the MOST wavelengths has the highest frequency.

Wave 2 has 4 → highest → Wave 2

Q5: Which wave has the lowest frequency?

Fewest wavelengths → Wave 3 has 1 → Wave 3

Q6: What is the definition of frequency?

Frequency is how often something happens in a given time. For waves, it’s how many complete waves pass a point every second. Measured in Hertz (Hz).

Simple answer: The number of waves that pass a point in one second.

Q7: How can you tell by looking at it if a wave has high or low frequency?

If the waves are close together (many waves in a small space) → high frequency.

If the waves are far apart (few waves in the same space) → low frequency.

So: High frequency = waves are squished together. Low frequency = waves are spread out.

---

Part 3: Frequency Connection (Family Voices)

Given:

- Dad: deep, low voice → low pitch → low frequency
- Mom: medium-high voice → medium frequency
- Baby: highest voice → highest frequency

Which wave belongs to whom?

Recall:

- Wave 1: 3 wavelengths → medium frequency
- Wave 2: 4 wavelengths → highest frequency
- Wave 3: 1 wavelength → lowest frequency

So:

- Dad (lowest) → Wave 3
- Mom (medium) → Wave 1
- Baby (highest) → Wave 2

Thus:

Q8: Dad → Wave 3
Q9: Mom → Wave 1
Q10: Baby → Wave 2

---

Final Answers:

A: Crest
B: Wavelength
C: Amplitude
D: Trough
E: Wavelength
F: Amplitude

1. 3
2. 4
3. 1
4. Wave 2
5. Wave 3
6. The number of waves that pass a point in one second.
7. High frequency waves are close together; low frequency waves are spread out.
8. Wave 3
9. Wave 1
10. Wave 2