Science and Technology
Understanding Structures And Mechanisms
Health and Physical Education
Engineering for Natural Disasters
75 minutes (can be split into two 35 minute blocks, if needed)
Investigate the force of wind and its effect on a tower they construct themselves. Learn about tornadoes and work in teams to design, build and test the strength and stability of their structures and their ability to withstand the force of wind.
The Grade Three learners will:
- Investigate, through experimentation, the effects of pushing, pulling, and other forces on the shape and stability of simple structures
- Describe ways in which the strength of different materials can be altered
- Investigate, through experimentation, how various materials and construction techniques can be used to add strength to structures
- Apply their understanding of good safety practices by developing safety guidelines for a variety of places and situations outside the classroom
a) Learners – Required Prior Learning
- This lesson is best taught along with the Science and Technology: Understanding Structures and Mechanisms - Strong and Stable Structures strand
- Students should have an understanding of what a structure is, what strength and stability are, be able to define “force” and give examples of some forces (push, pull etc.)
- Students will need to know how to measure at least 20 centimetres with a ruler
b) Learning Environment
- Students will sit at their desk for the lesson
- Students will work in groups of 3 at a desk for the experiment
- Students will complete the assignment independently at their desk
- Toothpicks (several boxes)
- Popsicle sticks (several boxes)
- White glue and rulers
- Masking tape, glue gun, glue gun glue sticks, blackboard/whiteboard, chalk/ whiteboard markers
- Table fan (with low and high speed settings)
- Safety goggles for group members conducting wind test and for teacher
- Wood boards (one for each group, approximately the same size)
- Copy of Engineering for Natural Disasters worksheet (attached)
- Photos of bridge collapse from an earthquake, windows blown out of a high rise building from a hurricane, damage to a home from a tornado
- Photo of a tornado
- Copy of Tornado Info Sheet (attached)
Introduction to the effects of forces of nature on human-built structures
b) Establishing the Learning
Identification of what is an emergency
Identification of various types of natural emergencies.
Recognition of relationship between natural emergency (tornado) and the effect of wind, a force, on a structure’s strength and stability.
Identification of safety procedures to be followed in the event of a tornado
Post one of the three photos (bridge collapse from earthquake, high rise windows broken from hurricane or home damaged by tornado) on the board and ask the students what has happened in the photo. When a few answers have been given, explain that a natural emergency caused the damage seen. Assist the students if they have not guessed the type of natural emergency that caused the damage. Ask the following:
1. What force or forces would have caused the damage to the structure?
2. Do you think that the engineers who build these types of structures could better design them so that they withstand damage from this sort of natural emergency better? If so, by doing what?
Repeat the above process with the remaining two photos.
Ask the students to define what an emergency is. When several students have had the opportunity to define emergency, provide them with the definition below:
An emergency is a situation that could cause damage to property and put people in danger.
Explain that emergencies can affect one person (medical emergency – child choking), a few people (house fire) and sometimes a whole neighbourhood or village/town/city (flood).
Explain that today they will be focusing on emergencies that can affect a whole neighbourhood or a whole village/town/city. Tell the students that the focus will be on natural emergencies, or emergencies that are caused by the forces of nature.
Ask students to name the types of natural emergencies they know about. These names should be recorded on the board. When complete, circle those that are wind-related (tornado, hurricane, windstorm, etc.) and explain that today the force being examined will be wind.
Remind students of their prior learning related about structures, strength, stability and forces. Explain that a natural emergency like a tornado produces very strong winds (show the photo of a tornado). The wind produced by a tornado is a force that acts on the structures around it by pushing on them. This push can impact on a structures strength and stability.
Explain to students that tornadoes are rare, they can happen anywhere in Ontario and they can cause serious damage to homes, buildings, bridges and the natural environment.
Explain that there are steps that people can take to stay safe in the event of a tornado. Hand out the Tornado Information Sheet and go over it with the class. Students can take this home and share it with their parents.
Consolidation of Learning
Tell the students that they are going to be building a tower today out of popsicle sticks and/or toothpicks. It is their job to act as natural disaster safety engineers and design the tower so that it can withstand the push of very strong wind gusts. Before they begin, the teacher should have them answer the following questions to ensure that they understand the key concepts (these can be written on the board):
- The natural force being examined today is ______. (wind)
- Winds can _______ on a structure. (push)
- A force that pushes on a structure can affect its _________ and _________. (strength and stability)
- A tornado is a cone of _____________ air. (spinning)
- Most tornadoes occur ________ through _____________. (May, September)
- In a tornado, it is best to go to the ___________ level of your home. (lowest)
Explain that students will work in groups and design a tower at least 10 cm in length, 10 cm in width and 20 cm in height. They are allowed to use as many toothpicks and or popsicle sticks as they want but that they only have 20 minutes to construct their tower.
Explain that once the 20 minutes are up, students will have their group’s tower tested. Its base will be glued with a glue gun to a wood board and placed 20 cm away from a table fan. The fan will be set to low for 20 sec and high for 20 sec to simulate the high winds associated with a tornado or other windstorm. Each group member will record what happens to their structure individually on their Engineering for Natural Disasters worksheet as their structure is tested.
The teacher should then divide the class into groups of three. Provide each group with the following: white glue, box of toothpicks, box of popsicle sticks, a ruler and a copy of the Engineering for Natural Disasters worksheet.
When the students have had a chance to get organized, start the clock.
After 20 minutes of building the structure, provide 10-15 minutes for the students to draw their structure in the space provided on the Engineering for Natural Disasters worksheet. During this time, circulate around the room and use the glue gun to adhere the base of each group’s tower to a wood board for testing purposes.
When ready, test each group’s tower ensuring students will be safe from flying debris.
During each test, students should record their findings in the Observations section of the Engineering for Natural Disasters worksheet. Students should write down or illustrate what worked and what did not. A final drawing of what the structure looked like after the test is also required.
The worksheet should be handed in for evaluation.
Observe students throughout the lesson and experiment to ensure that they understand the concept of force and that a natural emergency like a tornado produce a force, in this case wind, that can test a structure’s strength and stability.
Expectations should be evaluated using the attached rubric. Use the completed worksheet and observations to determine student performance.
Additional Related Activities
- Allow student groups to come up with a name for their natural disaster safety engineering firm before the experiment
- Try other experiments such as a shaking test, where a structure is built and then tested to see how it would survive an earthquake
- Invite a safety engineer to the classroom to talk about what they do
Tornado Information Sheet
What is a Tornado?
Some severe thunderstorms can produce tornadoes. A tornado is a cone of spinning air that comes out of a cloud and touches the ground. Tornadoes are most likely to happen May through September but they can happen at other times of the year too. Most tornadoes happen in the afternoon or early evening.
Tornadoes are dangerous because they can move quickly and they can produce very strong winds that can damage trees and homes. The objects picked up by a tornado, can be dangerous when they are thrown around by the tornado. Tornadoes can damage power lines and telephone lines so there may be power outages and telephones may not work. If power lines are lying on the ground they can be very dangerous.
How Will I Know If There Is Going To Be A Tornado?
Environment Canada lets people know when tornadoes may happen by putting out a Tornado Watch, or a Tornado Warning. The Tornado Watch or Warning is then broadcast by local radio stations, local television news/weather stations and on weather radio. A Tornado Watch and a Tornado Warning are different.
Tornado Watch – Severe thunderstorms have developed and may be able to produce tornadoes.
Tornado Warning – A severe thunderstorm has produced a tornado or tornadoes.
If a Tornado Watch has been issued for your community, it means you should prepare for a tornado (bring in lawn furniture, change outdoor plans, bring pets indoors etc.). You should also make sure to listen to the radio in case the Watch is updated to a Warning.
If a Tornado Warning has been issued for your community, it means you should be prepared and a tornado could happen at any time.
Sometimes, tornadoes can happen when no warning has been put out by Environment Canada. There are tornado danger signs you should watch for, especially during a bad thunderstorm. Things to watch for include:
- A dark green, yellow or black sky
- A cloud in the sky that looks like in has a dipping tail
- A cloud that is moving in circles
- A load freight train-like sound
How Can I Stay Safe If There Is A Tornado?
There are things you can do to make sure that you stay safe in a tornado. Here are some things to remember:
- Prepare an emergency survival kit and prepare a family emergency plan.
- *** We will talk about this at a later time
- Learn about whether tornadoes are likely to happen in your community. Ask your parents/guardians to call your local Community Emergency Management Coordinator (CEMC) and ask if your community is likely to get tornadoes. If so, find out if they have any information about how to prepare for a tornado.
- Stay informed. When the weather begins to look dangerous, listen to the radio and/or tune into local television news stations. It is best not to use televisions and other things that require electricity during a thunderstorm. Sometimes, if conditions are right, lightning can travel through wires and pipes and cause damage to property and/or injure people. In a thunderstorm, use a battery-operated or crank radio to find out what is happening.
- Find out where the safest place in your house/apartment to be in a tornado. It is best to go to the lowest level of a house (the basement is best), find a space away from windows or tall furniture and get under a large piece of furniture. If you do not have a basement, go to the lowest level and find an area with no windows. A hallway in the middle of your house or a small room like a cupboard or bathroom is best. In a very tall building, you may not have time to get to the lowest floor so it is best to go to a hallway in the middle of the building.
- If you hear or see a tornado coming or a Tornado Warning has been put out, go to a safe place right away. Tornadoes can move very fast.
- If you are in a car or mobile home, go to the basement of a close building. Cars and mobile homes can be picked up and tossed around by a tornado. They are not safe places to be.
- If you are in a car or mobile home and there are not any buildings nearby, lie flat in a low spot on the ground. Cars and mobile homes can be picked up and tossed by a tornado. It is safer to lie flat and let stuff in the air from the tornado blow above you.
Engineering for Natural DisastersAn Investigation
*** Complete This Page During Investigation
My Engineering Team:
___________________ ___________________ ___________________
Our Job (what you have to build and why):
Some ideas we have for increasing the strength and stability of our tower are: (labelled drawings or words)
*** Complete This Page During Investigation
Below is a drawing of our completed tower:
Make sure to label the following:
- Any special features (struts, ties or other design features) that increase your structures strength and stability.
- The top and base of your structure
- The length, height and depth of the tower (draw anand write the measurement above arrow)
*** Complete This Page During Investigation
Here is a sketch of our tower with the fan on low:
Here is a sketch of our tower with the fan on high:
Some things that we did that helped to improve the strength and stability of our tower were:
Some things that we did that did not help to improve the strength and stability of our tower were:
If I had to build this tower again for the same investigation, I would:
Describe two things people can do to stay safe when a tornado warning is issued?