8I Fluids

These statements are about the particle model of matter. Which one is not correct?

• Liquids are hard to compress because their particles are very close together

• Gases expand to fill their container because there are only weak forces between the particles

• Liquids can flow because there are only very weak forces between the particles

• Solids have a fixed shape because there are very strong forces between the particles

Tags

NGSS.MS-PS1-4

Why do solids expand when they are heated?

• The particles get bigger

• The particles vibrate more and take up more space

• The particles vibrate more and get closer together

• The particles stick together

Tags

NGSS.MS-PS1-4

Density is

• the weight of a fixed mass of something

• the volume of a fixed weight of something

• the weight of a fixed volume of something

• the mass of a fixed volume of something

What happens to the density of a block of iron when it is heated?

• It increases, because the volume increases

• It increases, because the volume decreases

• It decreases, because the volume increases

• It decreases, because the volume decreases

The pressure in liquids and gases is caused by

• the particles pressing down

• the particles pushing up

• the particles moving sideways

• the particles moving in all directions and colliding with things

When a gas is compressed

• the particles bump into the walls of the container less often

• the pressure drops

• the particles become more spread out

• the pressure increases

Why does a submarine need to be stronger than a ship of the same size?

• Water pressure is greater near the surface of the water

• There is more water pressure at the bottom of the sea

• Submarines carry more cargo than ships

• Water pressure decreases with depth

How can you work out whether or not an object will float in water?

• Find its weight

• Find its mass

• Compare its volume with the volume of water

• Compare its density with the density of water

Why does a hot air balloon float in air?

• Air is less dense than water

• The density of hot air is less than the density of cold air

• Air is denser on cold days

• The overall density of the balloon and its basket is less than the density of the air

Blocks of the same size but different materials are floating in a tank of water. There is more of block A beneath the surface than there is of block B. Which statement is correct?

• Block B is denser than block A

• Both blocks have a density greater than 1 g/cm³

• Block A is denser than block B

• You cannot say anything about their densities based on this information