номер 1, страница 152 - гдз по английскому языку 10 класс (spotlight) учебник Афанасьева, Дули

Science Across the Curriculum

Exercise 1, Page 152

Heating Things Up

Temperature

Everyone understands temperature.

We all can tell the difference between a sunny summer day and an icy winter day.

We realize when our tea is the right temperature to drink or when it will burn our tongue.

Yet temperature is hard to define.

What exactly is it?

A simple way to define temperature is to say that it is the number that you read on a thermometer.

But what is the thermometer measuring?

A more complicated answer is that a thermometer measures the average kinetic energy of a substance or an environment.

In other words, it is measuring how fast the molecules that make up the substance are moving.

A higher temperature means the molecules are moving more quickly.

Heat

But isn't heat the same as temperature?

Well, no.

Actually, heat is energy.

It is measured in joules.

When we feel that something is hot or cold, we feel the transfer of energy from a hot object to a colder object.

This transfer of energy from hot to cold goes on all the time.

This is why a cup of tea sitting on a table cools and why the ice in a glass of water melts.

Heat versus Temperature

Although heat and temperature are not the same, they are related.

If you add energy to a substance in the form of heat, the temperature of the substance usually goes up.

But sometimes the state of the substance changes. For example, ice melts and water boils.

We can see the difference between heat and temperature if we think of a pot of water on the cooker.

If you heat a little bit of water, it boils quickly.

But if you heat a full pot of water, it takes longer to boil.

Both pots of water boil at the same temperature, but the full pot requires a lot more heat to reach that temperature.