Electricity and the Domino Effect

What you'll need

• Laptop, projector and screen 
• “Electricity in Human Cells or Transmission Lines?” student handout, print one copy for each student
• Scissors, one pair per student
• “Electricity in Human Cells or Transmission Lines?” handout answer key
• “Domino Effect” student handout, print one copy for each student
• “Electricity and the Domino Effect” slideshow
• 6 sets of dominoes, approximately 28 dominoes per set
• Video: https://www.youtube.com/shorts/b4KP3pD1T6c

Introduction

1. Discuss how electricity powers lights and devices.
   • Option: use the activity “How does electricity power our lights?”
2. Explain that our bodies also use electricity.
   •  Option: do “Electricity in our bodies.”

Human Cell or Transmission Line?

1. Give students the “Electricity in human cells or transmission lines?” handout.
2. Have students cut out the statement squares.
3. Explain that each statement belongs to Electricity in human cells, Electricity in transmission lines, or Both.
4. Students sort the statements into the correct columns.
5. Review answers as a class using the answer key.

Domino Effect

1. Discuss how in both the human body and transmission lines, there is a chain reaction. Something needs to trigger the transmission. 
   • Ask students what an example of a trigger event might be in the body? (i.e. touching something hot, reaching out to catch a ball) 
   • What about the transmission line? (i.e. electricity generation at a dam)
2. Review the difference between potential and kinetic energy.
   • When the dominoes are lined up and standing, do they have potential or kinetic energy? (potential)
3. Put students into 6 groups. Give each group dominoes and each student the Domino Effect handout.
4. Get students to complete Experiment 1 together, have them discuss the results, then move to Experiment 2.
5. Once students have completed the two experiments, pull up the “Electricity and the domino effect” slideshow. 

6. Open the “Electricity and the domino effect” slideshow.

1. Slide 2 - Ask learners to share how the chain reaction of falling dominoes compares to the nervous system. 
2. Slide 3 - Explain to learners that triggering a signal means the dominoes won’t fall unless they are pushed. Just like a neuron won’t ‘fire’ until it receives a stimulus. It is also an ‘all or nothing’ response, when the first domino falls it triggers the next one completely. Similarly, a nerve impulse is an all or nothing event. Once the threshold is reached the impulse travels at a constant speed and intensity.
3. Slide 4 - Ask learners to share how the chain reaction of falling dominoes compares to the electricity in transmission lines.
4. Slide 5 - Explain that there is an activation energy & an energy transfer, both relate to the ways the dominos move to transmission lines. 
5. Slide 6 - Ask learners to share what happened when they pushed the first domino? The ‘break’ in the line of dominoes causes the ‘domino effect’ to fail. It stops the chain reaction from going further. 
   • Ask students to share how does this outcome relates to the nervous system?
6. Slide 7 - Explain to the learners that in the nervous system a break in the transmission of a nerve impulse could be due to a physical injury like a spinal cord or nerve injury. Damage creates gaps preventing the impulse from propagating past the affected area.
7. Slide 8 - Ask learners to share how transmission lines relate to the dominoes break. 
8. Slide 9 - Explain that a missing domino is like a fallen power line or pole. Ask students what might cause this kind of break in a transmission line? Discuss the different outcomes based on where that line might break. 
   • For example, if a power pole falls in a neighbourhood, then that neighbourhood might lose power. But if a pole falls somewhere before a substation, which then redirects power to different areas, then whole towns, communities or regions may lose power. This is a cascading or domino effect.
9. Slide 10 – Show learners this video: https://www.youtube.com/shorts/b4KP3pD1T6c
10. Slide 11 - Share that BC Hydro employs a multi-faceted approach to prevent cascading power outages. These include: 
    • anti-cascading towers that limit the "domino effect" if one tower fails, preventing the failure from spreading along the line.
    • non-combustible poles made of fibre-reinforced polymers to replace damaged or aging wood poles.
    • fire-resistant pole wraps are a pilot of steel mesh wraps with a heat-activated coating to shield poles from radiant heat and flames during wildfires.
    • planned upgrades and maintenance.
11. Slide 12 - Share that transmission lines often travel long distances over many obstacles. Discuss types of natural obstacles they must cross in B.C. such as, mountains, valleys, rivers, lakes and corners.
12. Slide 13 - Challenge the groups to build one line with their dominoes and add at least 2 obstacles. One of the obstacles must change the height and it must go around at least one corner. They may also want to build bridges over gaps. Allow them to experiment with what works best and be creative with their ideas.
13. Slide 14 - Share that B.C.’s longest single transmission line is the North Coast Transmission Line (NCTL) project, which will be approximately 450km long between Prince George and Terrace.
14. Slide 15 - Challenge the class, again, to create one continuous transmission line with all 6 sets of dominoes, including many obstacles and corners and test to see the current move the whole way around without breaking the circuit. Take a video or photo of your class creation and share with BC Hydro

We would love to see your photos and videos of your domino lines, email them to us at schools@bchydro.com