ingridscience

Mobile

Summary
Make a mobile and relate to forces in balance.
Materials
  • twigs/skewers/flower arranging wire for mobile sticks
  • sewing thread/embroidery thread for hanging
  • pine cones, feathers, natural materials for hanging
  • origami paper/card for art to hang
  • wire cutters, scissors, hole punch, stapler
  • tape and glue gun
Procedure

Show students ideas of mobiles.
Ask them to draw their mobile, probably best with just two sticks for time, and more interesting if one stick hangs from another so the balance point is not in the centre (see first photo).

For materials, thicker twines (e.g. hemp) and heavier objects (e.g. pine cones) allow students to do more of the tying themselves.
For hanging origami, embroidery thread can be stapled to the paper.

When they start to build it, students should work up from the bottom of the mobile.
First hang the materials to each end of the bottom stick, then hot glue in place.
Then attach the thread and move it sideways along the stick until this bottom stick is balanced (ask students to predict where the balance point will be if they have done activities on balance points and relative masses already). Then hot glue in place (with as little hot glue as possible so the balance is not upset).
Then attach the top of this thread to one side of the next stick up (or more centrally if the students prefer a more symmetrical mobile). Add (an)other object(s) to the end(s) of the stick. Tye the hanging thread and move it until the balance point is found, before hot-gluing in place.

Notes

See balanced hanging wire structure: Steven Caney's building book p.292
Mobile math: https://www.teachengineering.org/activities/view/cub_art_lesson01_activ…

Grades taught
Gr 4
Gr 5

Mirrors for looking round corners

Summary
Use a mirror to look around corners.
Science topic (2005 curriculum connection)
Physical Science: Light and Sound (grade 4)
Materials
  • small mirror
  • pieces of paper and pencil
  • piece of card
Procedure

Draw/write something on the piece of paper.

Place the drawing behind the card so that it is not visible.
Find the place to hold the mirror so that you can see around the card at your drawing.

Stick the drawing on the underside of a table.
Find the place to hold the mirror so that you can see under the desk at your drawing.

Play around with other ways of using the mirror to see around corners/behind you etc.

Notes

Make a periscope

Grades taught
Gr 1
Gr 2
Gr 3

Catapult from tin can / poster tube

Summary
Make a catapult from a recycled can or piece of poster tube, to shoot foil balls 10m and beyond.
Science topic (2005 curriculum connection)
Physical Science: Force and Motion (grade 1)
Physical Science: Forces and Simple Machines (grade 5)
Materials
  • plastic spoon
  • popsicle stick, clipped to the length of the spoon handle
  • duct tape, about 20cm (masking tape, pictured, does not hold up to the forces)
  • two mini binder clips
  • mini cup-cake holder, or fashion a bowl from tin foil to fit in the scoop of the spoon
  • elastic bands of various lengths and thickesses, #32 works well
  • tin can with both ends removed e.g. soup can, or piece of poster tube. The diameter must not be wider than the handle of the spoon.
  • aluminium foil, to make ammunition balls
  • an open area, where students can fire their ammunition 10m or so
  • measuring tape to record distances, or mark out the area with lines 1m apart
Procedure

To make the catapult arm:
Tape the short popsicle stick to the spoon handle, to reinforce it.
Lay the end of the spoon handle over a silver handle of the binder clip, and temporarily open up the binder clip, so you can tape them together tightly with duct tape.
Use a small loop of tape to secure the min cup cake holder in the scoop of the spoon - this makes a deeper bucket for the ammunition.

To attach the catapult arm:
Clip the spoon handle with its binder clip to one lip of the tin can, so that the catapult arm can swing up to the other side of the can.
Attach the second binder clip to the other side and the other end of the can.
Loop an elastic band over the scoop of the spoon, across the can, and behind the inside handle of the second binder clip. The catapult arm should be pulled up against the rim of the can.
One of each of the binder clip handles can be flipped back, to make the attachment more secure.

To fire the catapult:
Make ammunition from balls of aluminium foil.
Load the ammo in the bucket, while tilting the catapult backwards, so the ammo doesn't fall out.
Pull back the arm of the catapult by the reinforced handle, while moving the can back to its horizontal position.
Let the arm go. The ammunition should fly several metres.
(In the classroom students can fire the catapult without any ammunition, to understand how it works.)

Discuss the forces and energy transfers:
When you pull the arm back, energy is stored in the elastic band. As the arm is released, the elastic band contracts again, exerting a force on the catapult arm and pulling it forward again. The bucket of the catapult exerts a force on the ammunition, pushing it forward with it. When the arm hits the can, the ammunition has no force to stop it from moving, so it continues to project forward. Gravity pulls the ammo downwards as it moves, so it makes an arc across the room.
The catapult is a class 3 lever, with the effort (the elastic band pulling on the catapult arm) between the fulcrum (the binder clip hinge) and the load (the bucket). The bucket moves further than the spoon handle, but experiences less force at one time (though has plenty of force to move the ammo forward).

Discuss Newton's Laws in the catapult:
1st Law: Focus on the ammo - catapult arm makes it move. Gravity makes it fall. Air slows it down. The ground pushing up makes it stop.
2nd Law: F=ma. A greater force (stronger band/pulled back more) will make it go further. A larger mass will go less far.
3rd Law: At each step there is a force pushing back on the ammo, even when it is still. When one force is greater than the other, the ammo moves or slows down.

Take the students outside to fire their catapults.
Scrape out lines in a gravel field or chalk up concrete, to provide the students with metre marks from a firing line. Students can stand on the line and measure how far their ammo flies each time.

Change the forces:
Ask students how they can make their catapult fire further (also helps students that are having trouble). Ideas: make the elastic band stronger by doubling it up, or switch for a stronger elastic band. I use three elastic sizes, #32 to start with, then add in #16 and #64. The sizes do not matter, but these bands do work.

Graph the results:
Ask students to record their distances for each sized ammunition.
Graph the data, with students initialling their places on the graph (see photo).
Note that I have not been able to make any consistent pattern from graphing whole class distances, either from different sized balls or different elastic bands. Neither is there no clear correlation between the distances fired and different elastics when used by the same student with only a few data points.
It is still OK to graph and see that there is no distinct pattern - opportunity to ask what other variables there might be, and how to test for these. Also an opportunity to explain that sometimes we need more data to see if there are any patterns. I want to try students each graphing their own data - and collecting around 10 data points each. (I think they will also more naturally want to collect more data to find a pattern.)

Attached documents
catapult_distances_worksheet.pdf
metre_markers.pdf
Notes

If done outdoors in the cold/wet, tape the spoon to the popsicle stick for students beforehand.

Grades taught
Gr 1
Gr 2
Gr 3
Gr 4
Gr 5
Gr 6
Gr 7

Catapult - open wooden frame

Summary
Make a "viking catapult".
Science topic (2005 curriculum connection)
Physical Science: Force and Motion (grade 1)
Physical Science: Forces and Simple Machines (grade 5)
Materials
  • 6 bamboo skewers
  • wire clippers or strong scissors to cut the skewers
  • 11 elastic bands
  • small square of very strong fabric with three holes punched around the edge, or other material to make a pouch
  • aluminium foil to make ammunition
Procedure

Introduction:
I have seen this called a "viking catapult", based on how it is made up of rods lashed together.
The skewers model tree trunks, the elastic band models rope and animal sinews.

Procedure:
Clip the sharp tips off the bamboo skewers. Cut one of the skewers in half.

Refer to the image to see the final shape of the scaffold, and follow this order of construction if you like:
Use an elastic band to secure three skewers together at one end.
Use another elastic band to secure the other end of one of these skewers to two more skewers (at their end).
Take one free skewer end from each bundle, and bind them together - this should make a triangle.
Take the last free skewer end from each bundle, and bind them together - this should make a second triangle. The two triangles you just made have one skewer in common.
Hold the two triangles apart from each other and brace them open with the two short skewers, using elastic bands at each joint, as in the photo.

To make the ammunition pouch:
Loop an elastic band through each of the holes.
Two of these elastic bands can hook over the upright struts of the catapult.
The third elastic band should be secured to the bottom skewer with one or two half hitches.

Make ammunition from balls of aluminium foil.
Hold the ammo in the pouch as shown in the second photo, then release. It should go several metres.

Notes

Started this catapult in science club, but ran out of time. Too fiddly with the elastic band winding for grades 1 and 2.

Temperature measurements in a pond

Summary
Measure and record the temperature at a pond in several different locations.
Materials
  • thermometer
  • optional: thread tied to thermometer to access water under bridges etc - see note below
  • map and pencil for recording temperatures
Procedure

Show students how to read their thermometer, making sure not to cover their hand over the bulb.
Students make temperature measurements at different places in the pond. They record each temperature measurement on correct location on the map.

Discussion: was there a change in the pond temperature?
We found the shady spots were a little lower in temperature.

Attached documents
jericho_pond_map_and_worksheet_page_2.pdf
Notes

If a thread is used to suspend the thermometer from a bridge, be very careful not to snag ducks, turtles or other wildlife. Better not to use a thread if possible.

Grades taught
Gr 1
Gr 2
Gr 3

Freshwater pond study

Summary
Measure temperature in a pond and collect pond invertebrates to identify.
Curriculum connection (2005 science topic)
Earth and Space Science: Air, Water and Soil (grade 2)
Life Science: Habitats and Communities (grade 4)
Life Science: Diversity of Life (grade 6)
Life Science: Ecosystems (grade 7)
Materials
  • a pond with a variety of places to access the water e.g. in Vancouver: Trout Lake boardwalks, Jericho Beach Pond, Central Park native plant stream
  • materials listed in the activities
Procedure

Take the class to the pond.
Review the activities, and the pages of the worksheet (see attachment):
On the map, record temperature measurements where they are made; draw a pond invertebrate in the circle and point on the map to where you found it.
End with a scavenger hunt if there is time (we did not).

Attached documents
jericho_pond_map_and_worksheet.pdf
Grades taught
Gr 1
Gr 2
Gr 3
Gr 4

DNA and evolution

Summary
Look at different animals, discuss the differences and similarities between us and them, then extract the molecule that makes those differences: DNA.
Curriculum connection (2005 science topic)
Life Science: Animal Growth and Changes (grade 2)
Life Science: Diversity of Life (grade 6)
Physical Science: Chemistry (grade 7)
Materials
  • live animals to look at, if available
  • photos of the animal skeletons
  • materials for DNA activity
Procedure

Look at a collection of live animals (we had two reptiles: a bearded dragon and a snake) and name similarities and differences between us and them, in our bodies features and how we behave.

Bearded dragon discussion: we are both animals, we both breathe air, we both have legs. Note: bearded dragon has a hole for an ear. Show skeleton of lizard and us to show how similar to us they are.
Corn snake discussion: both animals. Snakes hear through jaw bone. No legs. Tongue for smelling. Show snake skeleton pictures.

What makes us all look different from them in some ways and different in others? What makes us look like we do?
DNA.

DNA has units ACGT. With a different order of units the instructions are changed.
Instructions very similar between people, more different between us and a snake, even more different between us and a wood bug [we had just looked at wood bugs too].

Isolate our own DNA, so you can see it.
We won’t be able to see the ACGTs, but can see strands stuck together.

Grades taught
Gr K
Gr 1
Gr 2
Gr 3
Gr 4

Respiratory and Circulatory Systems

Summary
Listen to your heart and feel your pulse. Model a working lung and listen to your own heart beat. Exercise to observe changes in your breathing and heartbeat.
Curriculum connection (2005 science topic)
Life Science: Animal Growth and Changes (grade 2)
Life Science: Plant Growth and Changes (grade 3)
Life Science: Human Body (grade 5)
Life Science: Diversity of Life (grade 6)
Procedure

Show an image of the circulatory and respiratory systems.
e.g. https://www.pinterest.ca/pin/843439836446359943/
The respiratory and circulatory systems bring O2 to cells of your body and takes away CO2 waste.
Respiratory system = lungs, mouth and throat. Brings oxygen into the body, and exhales CO2.
Circulatory system = blood vessels, heart which pumps the blood. Brings O2 to cells, removes CO2.

Show a beating heart gif: https://en.wikipedia.org/wiki/Heart#/media/File:CG_Heart.gif
Point out the valves closing one after the other, the 'lub dub' of the beating heart.
Students use stethoscopes to listen to the valves closing in their hearts.
I do not have one stethoscope per student, so they pair up, and one listens to their heart (in the silent classroom), while the other runs around the school/field once (makes the beats stronger and louder, so easier to hear). Switch after 2 mins. Switch a couple of times.
Your heart beats your whole life, pushing blood around your body to bring oxygen to every cell.
Your heart is a piece of muscle (meat). Optionally show images of cow heart.

Students feel their pulse, which is the push of blood in blood vessels with each heartbeat.
Use two flat fingers to feel for it.
Radial pulse - on the wrist just below the thumb (pulse in the radial artery).
Carotid pulse - on the side of the neck under the jaw bone. (One of the strongest pulses as it is close to the heart. The carotid artery supplies blood to the brain.

Calculate how many times your heart beats in your lifetime. Count 15 seconds.
(mine: 64 beats/minute = 30 thousand/year (more when I exercise) = 3 billion (^9) in a lifetime to 90).
This is an underestimate as it beats faster when you exercise.

The lungs bring oxygen into your body, and exhale carbon dioxide.
Lung model to show how air is drawn into the lungs as the diaphragm muscle contracts.

Breathing and heart rate before/after exercise activity:
Standing up, quiet in class, close eyes - listen to your own breathing. Feel your heartbeat if you can.
Exercise hard for 30 seconds (start clock when every student has started up). Go hard running on the spot.
Count down to standing still again. Close eyes.
What do you notice about changes in your breathing and heart? (see students' list in photo)
Breathing is deeper and faster. Might also notice your heart beating harder and faster.
When you exercise, your breathing rate and depth increases, and your heart beat gets stronger and speeds up. It is all automatic (you don’t think about it to make it happen).
When you work hard, your cells work hard - they use up more oxygen and release more CO2.
Your brainstem detects the increased CO2 in your blood, and signals your heart rate to increase and your breathing to become deeper.

Optional: activity to show what happens to the blood when CO2 increases: carbon dioxide acidifies water [blood] - the brainstem measures the acidity of the blood and so can sense when CO2 in the blood rises.

Deeper breathing means extra oxygen is brought into the body and taken up by the blood. And also more CO2 is exhaled from the body.
Harder and faster heart beats mean more blood is brought to the lungs, to pick up more oxygen, and get it to the cells. And more CO2 is removed.
Refer to the respiratory and circulatory system diagram, working as a system of parts (heart, lungs and blood vessels).

(You can use the cortex of your brain to override and slow down breathing by thinking about it.)

Find your blood
Now that you have looked at models of blood, let's look at the real thing that transports oxygen from your lungs to all fo your cells.
Find places that you can see your own blood.
Distribute flashlight to students, so that they can shine it through their skin and find the red of blood.
[Wrist, under tongue, eyeballs the blood is easily visible. Flashlight through closed fingers.]

Grades taught
Gr 4
Gr 5
Gr 6

Balanced/unbalanced Forces

Summary
Experiment with things that balance, and discuss the forces involved when they are balanced and unbalanced.
Procedure

Do a selection of the activities.

Start or end with Balancing your body challenges.

Finding the balance point of a stick or ruler can be done:
1. large scale, using long dowel rods, with fewer students, or with student groups. Large balls of homemade play dough are added to each side of a long stick and it is balanced on a finger, to explore how the balance point moves as the mass is redistributed.
2. small scale, using a (paint) stick or ruler and modelling clay/lego. The ruler can be used for quantitative measurement and graphing.

Make a mobile, using the principles learned above to quickly assess where the balance point of each stick in the mobile is.

Experiment with the centre of mass with a balancing sculpture.
Discuss that without the weights the toothpick is unstable and falls because the mass is above the balance point (the tip of the toothpick on your finger). The sculpture moves til the mass (or the average of the distributed mass; centre of mass/gravity) is low as possible and below the balance point. Adding weight below the balance point lowers the centre of mass and makes it more stable.

A rocket has balanced and unbalanced forces alternating before, during and after launch.
At rest before and after launch, the force of gravity on the rocket balances the force of the Earth pushing back up on it, so it does not move.
When launched, the force of the propellant pushing the rocket up is greater than the force of gravity pulling down (they are unbalanced), so the rocket moves upwards.
At the top of its trajectory, the force from the propellant is running out and is balanced by the force of gravity, so the rocket is stopped for a moment.
Then as the rocket falls, there is no upwards force, so the forces are unbalanced again, with the force of gravity winning over.

Grades taught
Gr K
Gr 1
Gr 2
Gr 3
Gr 4
Gr 5
Gr 7

Kingdoms of Life

Summary
Students collect samples from each of the kingdoms of life, then view them under microscopes.
Curriculum connection (2005 science topic)
Life Science: Diversity of Life (grade 6)
Procedure

Hunt for specimens from each of the Kingdoms of Life, then use magnifiers and microscopes to view them closely.

Notes on each Kingdom and how to magnify:
Animals are best viewed under dissecting microscopes, to see body parts within the whole animal. You can also look at cheek cells under the transmission microscope, to see . Daphnia can be put under the transmission microscope, but too large and moving too much.
Plants under either microscope. Tear a leaf to make an edge with a thin layer, to see individual cells.
Fungi - best under dissecting microscope, to see individual filaments.
Protists - transmission microscope. Separate out a few pond algae filaments, to view the line of cells (with nuclei and chloroplasts). Also single celled protists swimming among the algae filaments (if the algae has not dried out).
Monera - hard to find in soil because of all the dirt particles, but look for moving dots under 100X and 400X. Also find bacteria in a scoop of yogurt - look at it right away before it dries up under the hot microscope lamp.

Grades taught
Gr 5
Gr 6
Gr 7
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