Inquiry question:
How does the medium (air, water, or solid) affect the way sound travels?
Notes:
- Sound is produced by vibrations of an object.
- These vibrations make particles in a medium vibrate, passing energy onward.
- The denser and closer the particles, the faster and more effective the transmission.
Materials (per group):
- 2 tin cans (or sturdy paper/plastic cups)
- ~3–6 m of string (different materials if possible)
- Nail/awl/scissors to make holes
- Ruler or tape for measuring string length
Procedures:
- Prepare cans: Carefully make a small hole in the center of the bottom of each tin can (or cup).
- Thread string: Pass one end of the string through the hole in a can and tie a knot inside so it won’t pull through. Repeat with second can.
- Stretch the string: Groups spread out so the string is taut (this is essential — slack string stops the sound).
- Test sound: One student speaks into one can while another listens at the other can.
Results (take notes!!):
- Can the listener hear the speaker?
- What happens if the string is loose vs pulled tight?
- Does string length or material change how well sound travels?
- What do you think is vibrating — the can, the string, or both?
Analysis & Discussion:
Answer the key questions below in your School paper:
- Why were you able to hear through the string but not through air alone?
- What would happen if you tried this with no string or slack string?
- In which medium (solid, liquid, gas) do you think sound travels fastest, and why?
- Why can’t sound travel in a vacuum (even with cans)?
Conclusion & Wrap-Up:
Summarize the big ideas:
- Sound is created by ________________.
- These ______________ must travel through a ______________ (solid, liquid, gas).
- A _______________ doesn’t have particles → no sound transmission.
- Sound travels in ______________ more efficiently than in ____________ because____________.
Assessment:
Draw a diagram showing how the tin can telephone works (vibrations traveling through string).
Explain why sound can’t travel in a vacuum using evidence from the activity.
Compare how well sound travels in a solid (string) vs in air.