HEAT-POST -2

HEAT BLOG 2 

Dear students welcome .  This is our second class on the chapter HEAT 

IMPORTANT- KINDLY MARK YOUR ATTENDANCE ON THIS BLOG WITH A GREETING. DO NOT FORGET TO MENTION YOUR NAME AND ROLL NUMBER.

You will need : 

A SINGLE LINED NOTEBOOK WHICH IS NEATLY COVERED. MAKE SURE YOU HAVE USED THE INDEX AND WRITTEN TODAY'S DATE.

THE NOTEBOOK WILL BE EVALUATED SO KINDLY MAKE SURE YOU DO ALL YOUR WORK NEATLY.

At the end of this lesson you will be able to 

• Explain why heat is a relative term 
• Define Temperature 
• Name the device used to measure temperature 
• Name the different temperature scales 

Let us discuss another activity today:

You can definitely try this at home later

Take three bowls: Bowl A, Bowl B and Bowl C 

Fill them with ice cold water, luke warm water and hot water (bearable) respectively.
Dip your right hand into ice cold water and your left hand into hot water (make sure you won't get burnt).
Now dip both the hands into Bowl C of luke warm water.
What do you feel?
The right hand fingers feel water in bowl C to be warm.
The left hand fingers feel water in bowl C to be cold.

Which is right? 
Answer: BOTH ARE!!
Does this mean we cannot rely on or sense of touch to judge if something is hot or cold?
The answer is YES.

This is because of the principle that heat always flows from a hotter to a colder object. 
Hence:

• When heat flows from an object to your body it feels hot/warm (your right hand was cold so when immersed in lukewarm water, heat flowed towards your hand and it felt warm)
• When heat flows from our body towards an object it appears cold (your left hand was hot and when immersed in lukewarm water, heat flowed away from it, towards the water and thus the water felt cold)

When we measure the degree of hotness or coldness of a body on a chosen scale it is called Temperature

TEMPERATURE SCALES

Note: Celsius scale is the most commonly used for measuring temperature. Fahrenheit and Kelvin are two other scales used.

What is the name of the device used to measure temperature?
It is called a thermometer.

Digital Thermometer 

Laboratory Thermometer 

SDG- 13 (climate action) 

If the world temperature rises by 2 degrees, mountain glaciers and rivers will start to disappear and mountain regions will see more landslides.

Homework:

DRAW A  WELL LABELLED DIAGRAM OF  LABORATORY THERMOMETERS IN YOUR SCIENCE NOTEBOOK.

Answer the following orally-

1. In which direction does heat flow? 
2. Define Temperature 
3. Name two temperature scales.
4. Name the device used to measure temperature 
5. Distinguish heat and temperature (the link given below will help you)
6. Follow the link given below to get a better understanding of the concepts https://www.youtube.com/watch?v=I1AX6SINhFE
7. Find out more effects on the Earth with increase in average global temperature.

That is all for today

See you soon!