AUSTRALIAN CUB SCOUT
SILVER BOOMERANG REQUIREMENTS

Part 10 – Scientific Discovery

(The World Around Us)

Complete any TWO of the following
Biology
Observe how an animal, bird, reptile or insect develops and behaves

Report on your findings.

This is something that needs to be done at home, and can cover anything from a family pet to silkworms or mice.

 
Chemistry
Perform an experiment that shows the difference between gas, liquid and solid states A simple 2-part experiment that could be used here is to have the cubs light a candle (which also covers the Bronze match-lighting test), and to observe the wax that is converted from a solid to a liquid by the heat.
Next, pour a qty of vinegar into a cup, and mix in some baking soda. Hold a piece of cardboard that is folded (into a “V”) at an angle so that the bottom edge of the “V” is just above the flame. Now pour the GAS (not the liquid) from the cup into the top of the card, the gas should flow down and extinquish the flame of the candle.
Not only do we see the effects of the gas, but the remaining liquid wax will have become a solid again by the end of the next game or two.

 
Geology
Explain how volcanos erupt and earthquakes occur. When people think of volcanoes, the first image that comes to mind is probably a tall, conical mountain with orange lava spewing out the top.
A volcano is a hole where melted rock called magma or rock and ashes are thrown up from inside the earth. Volcanoes are commonly known around the world for bringing huge destruction as they erupt. When most people think of volcanoes they think of hot boiling lava. Many people do not realize that instead of only erupting lava, it also erupts ash and gas. A volcano works in the following sequence.
 
  1. Melted rock called magma rises from deep within the earth to near the surface.
  2. Some of it cools and becomes solid within the crust, but some erupts on the surface as lava.
  3. When two plates with ocean crust move apart magma from the mantle bubbles up to the surface to fill it.
    4. Because of this factor, the Atlantic Ocean is widening by about 2cms per year. The Pacific is widening much, much more as well. It is widening by 20cm per year.
    There are certainly many volcanoes of the standard type. But the term volcano actually describes a much wider range of geological phenomena.
    Generally speaking, a volcano is any place on a planet where some material from the inside of the planet makes its way through to the planet's surface. One way is "material spewing from the top of a mountain", but there are other forms as well. Also there are many different types of volcanoes. Some volcanoes are dormant, some are active, and some are dead or extinct.
    Earthquakes happen because the outer layer of the earth (the crust) is slowly being deformed by stresses that are placed on the crust. These stresses build up along locked portions of the crust where earthquake faults are. Eventually the stresses become too great for one of the faults to withstand, and the crust suddenly moves, like a spring that has been wound too tightly. This sudden movement of the ground is called an earthquake. Most of the stresses that cause earthquakes can be explained by the theory of plate tectonics. According to this theory, the crust of the earth is broken up into many tectonic plates--something like a cracked eggshell. Unlike an eggshell, however, the earth's plates are not fixed in one location, but raft above a partially molten layer of the earth which is about 60 miles deep. Where the edges of the plates meet, stresses build up, and earthquakes occur.

     
Show an experiment that illustrates one of these. Building a real working volcano
  1. First we need to create the 'salt dough'. Mix 6 cups flour, 2 cups salt, 4 tablespoons cooking oil, and 2 cups of water in a large bowl. Work the ingredients with your hands until smooth and firm. Add more water to the mixture if needed.
    NOTE – you could use modelling clay, sand, wire & paper-mache etc instead of making the salt dough. THEN “bury” the bottle in that instead. There is less to clean up if you use this option, and the sand type options are quicker to set up.
  2. Stand the soda bottle in the baking pan. Mold the salt dough around the bottle making sure you don't cover up the bottle mouth or drop any dough into the bottle. Take your time on this step and build your volcano with as much detail as you like.
  3. Fill the bottle most of the way with warm water mixed with a little of the red food coloring.
  4. Put 6 drops of liquid detergent into the bottle.
  5. Add 2 tablespoons of baking soda.
  6. Slowly pour vinegar into the bottle and jump back quick!
Notice the red 'lava' that flows out of your volcano. This happens because of the baking soda and vinegar mixture. Mixing baking soda and vinegar produces a chemical reaction in which carbon dioxide gas is created - the same gas that bubbles in a real volcano. The gas bubbles build in the bottle, forcing the liquid 'lava' mixture of the bottle and down the sides of your volcano.

 
Physics
Show that you understand the weather forecast Here is a sample forecast taken from the Bureau of Meteorology website
 
SYDNEY FORECAST Issued at 3:35 pm EST on Friday 2 May 20XX
 
Warning summary
Nil.
Forecast for Friday evening
Fine. Light to moderate west to southwest winds.
Precis: Fine.
Forecast for Saturday
Fine. Mostly sunny. Light to moderate south to southwest winds, freshening near the coast.
Precis: Fine. Mostly sunny.
 
City: Min: 12 Max: 20 Parramatta: Min: 9 Max: 19
Liverpool: Min: 8 Max: 20 Richmond: Min: 7 Max: 19
 
UV Index: 4 [Moderate] UV Alert from 10:20 to 13:20
 
Sunday Fine. Mostly sunny.
City: Min: 12 Max: 21
West: Min: 7 Max: 20
 
Other than pointing out that the forecast for "FINE" weather means that is will not rain, rather than the common misunderstanding that it means sunny, I am hoping that as a leader, you basically understand a weather forecast. However if not, the B-O-M site above has details of what it means.
Also available there are weather radar and other weather charts, for those who are interested in learning more about the weather.

 
Show how rain is formed (this information is from other sites)
Air cools either through expansion or by coming into contact with a cool object such as a cold landmass or an ice-covered area. When air passes over a cold object, it loses heat and its moisture condenses as fog, dew, or frost. Air also cools as it rises and expands. The water vapour in the cooling air condenses to form clouds and, sometimes, rain.
Air rises for several reasons:-
  • In orographic lift, the air is forced upward as it encounters a cooler, denser body of air or when it meets raised landforms such as mountains.
  • In convective lift, air coming into contact with a warm surface, such as a desert, is heated and becomes more buoyant than the surrounding air.
  • Convergent lift occurs in storms such as tornadoes. Air whirling toward the centre of a cyclone collides with itself and is forced upward.

In all three above, notice that the important factor that causes cloud, and then rain, is the warmer air rising and cooling.
For raindrops to form there must be particles in the air, such as dust or salt, at temperatures above freezing. When the particles are cooled to temperatures below freezing point, water condenses around them in layers. The particles become so heavy they fall through the clouds. In a thunderstorm, the rain particles may become very large and fall from the cloud as hail. When the air temperature is at or below freezing all the way to the ground, the particles will fall as snow.
The formation of rain clouds may be very local. During a hot summer day, air rising over a moist region may cause cumulus, or woolpack, clouds to form in the cooler air above the surface. These clouds darken to rain clouds as more moisture condenses. Frequently, the rain cloud is the only cloud in the area, the rest of the sky remaining sunny. Such rainstorms occur almost constantly in the doldrums - the hot, calm areas near the equator. Cumulus clouds can sometimes be forced to release rain by "seeding" them with particles of dry ice or silver iodide. Commercial rainmakers have claimed success using these methods.

 
Estimation
Estimate the following:
  • The distance from your scout hall door to the road
  • The distance from one end of the hall to the other
  • The height of a flagpole or tree.
 		You will need:
  • 1 ruler (per cub)
  • 1 scout hall (per pack)
  • 1 cub scout
Instructions –
  1. Place a mark on the ground/floor
  2. Place one toe on the mark, and step forward ONE pace
  3. Mark the position of the toes of your other foot.
  4. Using the ruler, measure the length of your pace in Centimetres
  5. Pace out the length of both the hall and the distance from the hall door to the road.
  6. Using the known length of your pace, work out how long the two measurements are.
  7. As for the height of the flagpole, this one is a matter of estimating how far the flagpole would fit along the wall of your hall. Eg, if it is probably half the length of the hall, you can estimate the height.
Using the shadow & stick method is even more accurate for estimating the height of the pole or tree.
  1. Get a stick (say a metre long) and hold it upright in the SUN (this will not really work so well at night)
  2. Measure the length of the shadow it throws
  3. Measure the length of the shadow of the pole or tree, and divide the length of the stick’s shadow into that number.
  4. Multiply the stick length by the result
    Thus using a 1M stick makes it easy, as the result number is simply the previous number in metres.

Explanation – Often it is not possible to accurately measure distances. For instance, the rulers we use are usually only 30cm long, but we want to measure something much larger, and that is why we estimate.
This task demonstrated one method of estimating. It uses an object of known length (pace or shadow) to estimate something much larger than that object.
A common use of this method is during a hike. The hiker counts how many paces they have taken to estimate how far they have travelled. Another is the odometer in a car, which in simple terms, works by counting how many times the car wheels have turned to estimate the distance the car has travelled.

 

 

© 2008 Ian Moggs - rights are given for copying and printing for personal use or use in cub-scout or similar groups.
Last updated 2nd June 2013.