Pressure 4

​Watch this video (4 mins)

Make sure to know:

• ​What is the atmosphere?

• ​What is the value of the atmospheric pressure at sea level?

• ​​What causes atmospheric pressure?

Multiple Choice

What is the average atmospheric pressure at sea level?

• 27, 000 Pa (27 kPa)

• 48,000 Pa (48 kPa)

• 100,000 Pa (100 kPa)

Fill in the Blanks

Atmospheric pressure is caused by the weight of _ on top of us.

​Watch this video (4 mins)

Make sure to know:

• How to include atmospheric pressure when calculating liquid pressure.

Fill in the Blanks

A diver holds his breath and dives into the sea from a boat to a depth of 25.0 m. First, calculate the liquid pressure exerted to the diver at this depth. Assuming the density of sea water is 1026kg/ $m^3$  and the gravitational field strength of earth is 10 N/kg.

(Do not include the unit when entering your answer)

Fill in the Blanks

A diver holds his breath and dives into the sea from a boat to a depth of 25.0 m. The atmospheric pressure is  $1.05\times10^5$  Pa. Now, using your answer from the previous question, calculate the total pressure exerted to the diver at a depth of 25.0 m.

(Do not include the unit when entering your answer)

Fill in the Blanks

The picture shows a diver working below the surface of a lake. The density of the water in the lake is 1000 kg/m³, the atmospheric pressure at the surface is 1.0 × 10⁵ Pa and the gravitational field strength is 10 N/kg. Calculate the pressure due to 15 m of water.

(Do not include the unit when entering your answer)

Fill in the Blanks

The picture shows a diver working below the surface of a lake. The density of the water in the lake is 1000 kg/m³, the atmospheric pressure at the surface is 1.0 × 10⁵ Pa and the gravitational field strength is 10 N/kg. Calculate the total pressure at 15 m below the surface of the lake.

(Do not include the unit when entering your answer)

​Watch this video (4 mins)

Make sure to know:

• ​How atmospheric pressure works in suction cups and drinking straws.

Open Ended

Explain why suction cups can only stick to smooth surfaces but not rough surfaces.

Hint: think about what happens to the air molecules.

​Watch this video (4 mins)

Make sure to know:

• ​How atmospheric pressure changes with altitude.

• ​How changes in atmospheric pressure affect our body.

Multiple Choice

What is altitude?

• how much something weighs
• the distance above sea level
• how big something is
• how far away something is

Multiple Choice

Atmospheric pressure depends on .......

• mass

• density

• altitude

• magnitude

Multiple Choice

As you climb up a mountain what happens to the air pressure?

• decreases
• increases
• stays the same

Open Ended

Explain why does the atmospheric pressure decrease as you go higher up a mountain?

Open Ended

State one effect to your body when there is a difference in pressure between the atmosphere and your body.