Pressure

It is easier to walk on soft snow in snowshoes than in shoes with high heels. How do snowshoes help people to walk on soft snow without sinking?

Snowshoes distribute a person’s weight over a larger area. So the pressure in the snowshoes is lower than the pressure in ordinary shoes, and this enables the person to walk on soft snow without sinking.

Liquid Pressure

When we are underwater, we feel the pressure on water on our ears. A body of liquid (pool for example), exerts pressure on an object (our ear for example) placed in it because of its weight.

The amount of pressure inside a body increases with depth. At greater depths, the weight of the liquid above is greater, so the pressure is greater.

Atmospheric pressure

The earth is surrounded by air called the atmosphere. The atmosphere is the result of the Earth’s gravitational pull on air molecules near the Earth’s surface.

Although we cannot see or feel the air molecules, they have weight. So the atmosphere exerts pressure on the Earth’s surface, known as atmospheric pressure.

Оба учащихся отвечают на вопросы по тексту одним или двумя словами:

What is easier to walk on: snowshoes or high heel shoes? __________________________________

In what shoes is the pressure lower: snowshoes or high heel shoes? __________________________

What part of our bodies feels the pressure when we are underwater? _________________________

Does the amount of pressure increase or decrease at greater depths? __________________________

What do we call the air that surrounds the Earth? _________________________________________

The pressure that atmosphere exerts on the Earth is called … ________________________________