Cartesian Diver

The video explains the principles of buoyancy and weight using a Cartesian diver model. It demonstrates how changing pressure in a sealed bottle affects the diver's buoyancy, causing it to rise, sink, or hover. The experiment uses a plastic straw, sticky tack, and water to create the diver. The video also compares this concept to how submarines use ballast tanks to control buoyancy.

What are the two main forces acting on an object submerged in water?

• Gravity and friction

• Magnetism and gravity

• Weight and buoyancy

• Friction and buoyancy

What is the purpose of using sticky tack in the Cartesian diver?

• To attach the straw to the bottle

• To make the straw float

• To add weight and seal the straw

• To make the straw colorful

How can you make the Cartesian diver hover in the middle of the bottle?

• By adding more water

• By adjusting the pressure just right

• By shaking the bottle

• By removing the cap

What happens to the air inside the straw when the bottle is squeezed?

• It expands

• It remains the same

• It compresses

• It evaporates

What is the relationship between the volume of the straw and its buoyant force?

• They are inversely proportional

• They are directly proportional

• They are unrelated

• They are equal

How do submarines control their buoyancy to sink?

• By reducing the weight

• By releasing air from the ballast tanks

• By increasing the speed

• By filling the ballast tanks with seawater

What is the role of compressed air in a submarine's ballast tanks?

• To force water out and increase buoyancy

• To cool the engine

• To decrease the volume

• To increase the weight