1)May I know what is the meaning of "independent variable" & "dependant variable" ?
An independent variable is a factor that can be varied or manipulated in an experiment (e.g. time, temperature, concentration, etc). It is usually what will affect the dependent variable.
In your science experiments, you will always be controlling the independent variable and measuring the effect it has on the dependent variable.
For example, if you want to find out if plants require water to grow, the factors you will control is the amount of water given each day. So water will be the independent variable. The dependent variable will then be the observed amount of growth of the plant.
2)What is the difference between the properties & the charateristics of something?
According to the Longman Dictionary,
Characteristics refer to a quality or feature of someone/something that is typical of them and is easy to recognise.
Properties refer to a quality that belongs naturally to something. [In this case, it might be something that you cannot see, eg healing power]
3)When we say that something has definite volume, does it means that it cannot be compressed?
At your level, this is what you know. As long as an object has definite volume (liquids/solids), it cannot be compressed. This leaves us with only gases (compressable).
For the 'Learning Questions' page, I have a question for question 3). What about a sponge? I know that once you release the sponge after squeezing it, it turns back to its original shape. However, you said that all solids cannot be compressed. As the sponge is a solid, why can it be compressed?
ReplyDelete-Yi Qian
Yi Qian, this is a very good question. A sponge is a solid, no doubt about that. If you take a closer look at a sponge, it actually has 'holes' in it. These 'holes' allow air to pass through. So when you squeeze a sponge, what you are squeezing out is the air trapped in these 'holes'. The sponge itself still retains its shape.
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