This is homework if you didn’t do it in class because you needed the time to finish the essay:

1. Explain why the can was crushed in the water.

2. Explain why pressure around us is so high, but we cannot feel it.

3. Explain why it is not possible for humans to swim too deep.

4. Given that atmospheric pressure is about 100 000 Pa, show that a square meter could support 10000kg (about 15 cars).

5. Calculate the weight force on 1cm2 of air at sea level, assuming the atmospheric pressure above.