11 million takeover day
introduction
What is going to happen...
You and a friend will be taking a science lesson on November 23rd!
The science in this lesson plan can be used for Year 4, but any year above that would be fine, even your own class. You should prepare for this before the lesson because you will need to find equipment (for showing web pages and carrying out you own experiment). You'll also want to know more than the class do, so some background reading is a must.
what you will need to do before the lesson to prepare...
You'll need to watch the Scicast 'Blubber Glove' experiment before you start. Watch the film a few times and read the instructions on how to repeat it yourself. You may want to try it yourself before showing the class.
Next, have some background information about hot and cold things, and what insulators are and how they work.
why does the water become cold when ice is added it it?
It takes heat to melt ice. When you add ice to a basin of water, the water cools down, giving up its heat to the ice, and the ice slowly melts. When you put your hand in the water, both the water and the ice are very cold.
what is an insulator?
An insulator is anything which keeps warm things warm, and cold things cold. Insulators stop heat from moving from one place to another.
what makes a good insulator?
Think of objects which stop you from feeling cold, or protect you from feeling hot things. A padded coat which is full of air keeps you warm on a cold day: air is a good insulator. An oven glove stops you from burning your hand on a hot tray: thick cotton is a good insulator.
The ‘blubber glove’ experiment shows that lard is a good insulator, and the rubber glove itself also helps (it is possible to do washing up in hotter water when wearing rubber gloves). Whether you are trying to protect yourself from heat or cold, an insulator will prevent heat from flowing.
what is happening in the 'Blubber Glove' experiment?
Body heat from the person's hand wants to flow into the cold water. This is what happens to the unprotected hand; as the hand’s heat is lost to the icy water, the person's hand becomes colder and colder. When the person's hand is protected by the layer of lard and the rubber glove, heat is prevented from flowing into the icy water and that hand remains warm.
where can insulation by fat be found in the real world?
Mammals and birds produce their own body heat and they need to keep their bodies at a certain temperature to survive. Many Arctic and Antarctic animals have a thick layer of fat (blubber) to protect them in the cold water.
Penguins and polar bears have a blubber layer to help protect them from the cold. Animals which live both in the water and on land usually have fur coats too. The fur acts as an insulator keeping them warm when they are out of water.
where else can you find insulators?
Insulators are necessary around the home. Thick padding is used to insulate the loft so heat does not escape out of the roof; hot pipes and hot water tanks are also insulated with thick and sometimes shiny material. These help save energy because less energy is needed to keep the house or water warm.
Thermos flasks keep hot drinks warm.
Insulators also help when you want to keep things cold. Cool boxes and some lunch boxes are padded to keep the food inside cool. Just as heat will escape from an uninsulated house, heat will flow into an uninsulated lunchbox, making your drink warm and your cheese sweaty.