1 of 13

2 of 13

Τετράδιο Εργασιών, σελ. 194 - 197.

3 of 13

Τετράδιο Εργασιών, σελ. 194 - 197.

It's hard to pull the newspaper up.

It's easy to pull the newspaper up.

4 of 13

Τετράδιο Εργασιών, σελ. 194 - 197.

The suction cup sticks to a smooth surface, but not to a rough one.

If I lift the suction cup a little from the side, I can easily detach it.

5 of 13

Τετράδιο Εργασιών, σελ. 194 - 197.

If I let air get under the ephemera or suction cup, I can easily lift them.

6 of 13

Τετράδιο Εργασιών, σελ. 194 - 197.

The ballon gets bigger.

7 of 13

Τετράδιο Εργασιών, σελ. 194 - 197.

8 of 13

Τετράδιο Εργασιών, σελ. 194 - 197.

9 of 13

Τετράδιο Εργασιών, σελ. 194 - 197.

Air has weight. Because of its weight, it causes pressure called atmospheric pressure. Atmospheric pressure decreases as the height above sea level increases.

10 of 13

Τετράδιο Εργασιών, σελ. 194 - 197.

1. Why does the box deform as we drink the juice?

The box crumples due to atmospheric pressure, since there is no air inside it.

11 of 13

Τετράδιο Εργασιών, σελ. 194 - 197.

2. If we make a second hole in the box, will it deform as we drink the juice? Can you explain your answer?

If we drill a second hole in the box, it will not wrinkle since the pressure will be the same inside it.

12 of 13

Τετράδιο Εργασιών, σελ. 194 - 197.

3. The Moon has no atmosphere. Can the astronaut use the suction cup?

He can't use the suction cup because there is no air to exert force.

13 of 13

Τέλος…