Let's find out, grade 2; How can we tell?

Now when my two boys and girls to listen I'll join science ladies bring you another let's find out. You know boys and girls. How are you today. Are you warm. Are you cold. All right everyone try something for me. Where is your right hand. Hold up your right hand your the right one. All right. Put your right hand against one cheek. Along the side of your face. Hold the palm of your hand of your right hand against your right cheek. Now keep it there. Does your hand tell you that your cheek is warm. I keep it there don't move it just leave it right where it is. Now put your left hand on the table or chair.

Hold both hands still. Now which is warmer your cheek or the wooden table. All right. Now leave your right hand where it is on your cheek and put your left hand on the top of your head which is warmer your cheek or your hair. All right keep your right hand where it is. Put your left hand on your shirt. Are your dress which is cooler your cheek or the material in your clothes. Did I phone you that time. I ask which was cool are you all right. No one is cool. Where are you. We'll need you to dry something for all of us miss school. When you walk over to the chalkboard to the blackboard in your room please. Maybe yours is green but not call it a

chalkboard you always put one hand on the chalk board and one hand on the chalk rail underneath the board is one cooler than the other. Which one is cooler. Well maybe they feel the same in your room do they. All right thank you. Mr. Hot. Will you walk over to the door of your room all the way over to the door. Is there glass in the door. Well can you reach it if you can reach it. Fine and if you can't maybe there's a window that you can reach. Put one hand on the glass in the door and one hand on the door frame the wood are the metal around it which feels cooler. Now

maybe your door is made of wood and maybe it isn't. Is there any metal at all on the door. How about the door knob or the place where you push against the door. Find out which feels cooler metal or glass. Put your hand on the glass and another hand on a piece of metal it's close to the door. Or on the door. Which one is cooler. Glass or metal. All right. Now come back to the table Miss kool and Mr Hot. Come back to the table. And listen very carefully. We've been finding out about warm and cool by feeling things with our fingers and hands. We can tell about some things by feeling them with our fingers. We can tell warm things from cool things can't we. But suppose we wanted to measure just how warm something was.

How could we do it. Who said by using a thermometer. Well good for you. If their mama deer will tell us just how warm things are. A thermometer will tell us that temperate your things Miss cool when you look at the thermometer that you have there on the table. Can you see the colored line. Good. Find a think in and of the color at the bottom of the thermometer. Does the line run up from that thickened bottom and. When I you know you already know that when the air is warm the line in the thermometer will be long don't you. When the air is cold or cool the line in the thermometer will be short. Isn't that right.

Now look at the thermometer again. Can you find some numbers on the thermometer. Look along the sides the side that long line look along the sides of the thermometer. Can you see some numbers written there. Show them to Mr. Hot. All right now Mr. Hot do you have a thermometer there in your room hanging on the wall somewhere. Look around. Can you find one. All right Mr. Hot go over to the thermometer. Can you see the line in the thermometer. If you can reach it put your finger on the place where the top of the line is. Now if you can't reach it perhaps your teacher will help you. Did you find the top of the line in the thermometer. Now look closely and see if you can read the number.

That is opposite the top of the line in the thermometer. Maybe teacher will have to read it for you if you can't see that high. What does it say. What does the numbers say. Well Arthur monitor here in the studio reads 70 at the top of the line. That means the air in this studio here is 70 degrees. Warm your thermometer will tell you just how warm the air is in your room how warm is the air in your room. Good. What was the number up there at the top of the line. Good. And that's how warm the air in your room is. Thank you Mr. Hot. Not only is cool pick up the glass there

moment you're on your table and look at it. Find the bulb and of the thermometer get in the bottom and the bobbin will be thicker. It will show the same color as the line. Maybe silver or red or blue or even some other color which color is yours. Ours is silvery here. Now my school hold the thermometer by the top way up at the top and put the bulb and the bottom and into the pan of warm water. Now hold it there. Mr. Hot Are you back at the table. Will you watch the line in the thermometer. Find a line in the thermometer and watch it. What's happening to it. Is it going up. Watch it. Keep your eyes on it. Is it still going up.

Oh our Mr. hot here in the studio says ours has just about stopped it's moving very very slowly. Is yours. Is it just about stopped. Well now no matter whether it's stopped or not Mr. Hot what number is close to the top of the line in your thermometer right now. Did you find the number good. What was it. What does that number tell you about the water in the pan. I wonder does it tell you how warm the water is. Was the water in the pan warmer than the air in your room. Now I don't know how warm the water that you have in that pan is but the water that we have here in this studio is one hundred

ten degrees. That's pretty warm it feels warm to our fingers. Now is cool. Take the thermometer out of the warm water and put it into the ice water. Mr. Hot. Lean over there and watch what's happening to the line in the thermometer. Is it going down. Watch it. Is it still going down. Is it going down fast or slow. It would go down fast in the beginning wouldn't it. Did yours. Is it still going down. Ours is slowing up it's way down your way down to one hour when it stops. Read the number at the top of the line. Is it almost stopped.

Is it damn close to thirty two or thirty four are thirty six. Well if you left that thermometer in the ice water long enough. Touching the ice. The number on the thermometer would say oh just a buyout 32 32 degrees. Now maybe you won't have time to let it go all the way down but it is going down isn't it. The numbers on the thermometer tell us just how warm the things are. The things that we're measuring we measure the temperature or how warm the air was in your room you measured how warm the warm water was and now you are measuring how warm the cold water is. Does that sound funny how warm the cold water is. Well that's what you're doing. All right you can hold it there until it stops. But listen while you're doing it

some thermometers are used to measure the temperature of the air. Some other kinds of the monitors are used to measure the temperature of liquids like the one you're using now in the water. Other thermometers are used to measure the temperature of other things. Have you ever seen a thermometer that measures the temperature of your body. Each their home a cure is made especially to measure a certain kind of thing and we must be careful not to use a thermometer to measure temperature is higher than the thermometer was made to measure. There's a monitor hanging on the wall was made to measure the temperature of air. The one that you are using now or the one that your mother has at home in the kitchen is made to measure the temperature of hot liquids. The one that the

doctor puts in your mouth when he finds out your temperature is made especially for that so never use a thermometer to measure the temperature of things unless you are sure you have the right one. When you remember that. All right. Would you be surprised to know that there are thermometers that measure some degrees of heat. And some that only measure a few do. Why don't you talk about thermometers and see if you can find out where some of those thermometers are used. Will you do that. All right. Let's find out imagine night in the studios on Allen St. Louis more of Education radio station.

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