Embedded Files
Safety
Safety
Avoid releasing the end of the stretched spring.
Avoid releasing the end of the stretched spring.
Slinkies are not social creatures - secure them tightly to avoid accidental release.
Slinkies are not social creatures - secure them tightly to avoid accidental release.
Don’t let them get tangled!
Don’t let them get tangled!
PXL_20230428_165637810.TS.mp4Class DEMONSTRATION
Class DEMONSTRATION
Sliny Wave Boundary Behavior:
Sliny Wave Boundary Behavior:
Two slinkies tied together
Two slinkies tied together
Materials and Set-Up
Materials and Set-Up
PXL_20230428_165618728.mp4Materials
Snakey (one for class demonstration)
Slinky (one for class demonstration)
Class 3 Handout (one per student + teacher copy)
Instructions
Have two different slinkies tied together (the long thin snakey and the regular class slinky). Tie them tightly together with a string while also connecting through the metal, but don't deform the slinkies (as seen in photo below).
Have students predict first then observe what happens when you send a pulse from the slinky to the snakey.
The videos show what can happen.
Repeat the process, including predicting first, this time sending a pulse from the snakey to the slinky.
Have students pay special attention to the boundary and the direction of the reflections seen there.
Simulation
Simulation
Use The Physics Classroom to show the simulation of the slinky effect.
The video on the left shows how to click through the simulation. Approximately 1 minute in shows a simulation of a wave crossing boundaries similar to our snakey/slinky wave pulse.
Lab Investigation
Lab Investigation
Slinky Pulses and Wave Behavior
Slinky Pulses and Wave Behavior
Safety: Ideally, students should wash or sanitize their hands and materials before and after touching any equipment. This lab works best with slinkies on a smooth surface like tables or flooring.
If placed on the floor, make sure that students do NOT attempt to jump on the slinkies.
Materials and Set-Up
Materials and Set-Up
Recommended Group size: 3-4 students
Materials per Student Group
Slinky
Metersticks
Stopwatch
String
Calculators (optionally one per student)
Slinky Pulses
Slinky Pulses
Pass out slinkies, stopwatches, and meter sticks to groups.
Allow students to carefully play with slinkies for 5 minutes. Set a time and let them know this is the time for careful play. If their slinky gets tangled, it will mess up their results. Slinkies should never bend back on itself or get tangled with another slinky.
Keep an eye on the safety of slinkies and students at all times.
Allow students to play while working on the questions. Encourage detailed drawings and observations.
After 5 minutes of play, pass out the lab questions and tell students that it is time to work on the lab.
What happens when pulses overlap?
What happens when pulses overlap?
Students should make transverse waves where the pulses overlap.
The photo directly below shows two wave pulses that are about to constructively interfere.
The photo below shows two wave pulses about to destructively interfere.
PhET Simulation
PhET Simulation
SuperpositionWS.mp4Use this PhET simulation to show the simulation of the slinky effect.
The video on the left shows how to click through the simulation. The gif below shows the superposition of pulses.
Reflections
Reflections
Reflections from fixed ends versus loose ends can also be seen in the simulation above. Students should become familiar with the language used to describe the reflections as "inverted" or "upright." Students should be able to see this phenomena happening in real life with the slinkies as seen in the videos below.
Standing Waves
Standing Waves
Have groups of students spread out. This demonstration works well on a smooth floor, but you can also try to have students attempt the demonstration upright as seen in the videos below.
PXL_20230430_235253872.TS.mp4PXL_20230430_235242003.TS.mp4Set Up the Standing Wave Generator Demonstration
Show the students the nodes, antinodes and vary the tension of the string.
The video to the left shows the set-up and how to make standing waves in the classroom. It also goes into details for wave-particle duality, which we found to be beyond most 5-6 graders grasp. We recommended watching from 55 seconds to 3 mins and 19 seconds. (Please do not set the string on fire.)
The videos below show how to set it up horizontally. You can use a student to help with the demonstration if you wish for more stability than our ring stands can support.
PXL_20230609_230224643.TS~2.mp4PXL_20230609_230259608.TS.mp4Page updated
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