8I — Fluids

Question 1

What are the properties of:

1) Solids
2) Liquids
3) Gases

Answer 1

1) Solids
— Fixed shape
— Fixed volume
2) Liquids
— Fixed volume
— Take shape of container
3) Gases
— Expand to fill container
— Take shape of container

Question 2

What is a fluid?

Answer 2

Fluids are liquids or gases.

Question 3

What is density?

Answer 3

The amount of mass that one cubic centimetre of a substance has.

Question 4

1) What is the formula for density?

2) What are the units for density?

Answer 4

1) Density = Mass/ volume

2) The units for density are g/cm3 or kg/m3.

Question 5

1) What is melting?

2) What is evaporation?

Answer 5

1) Melting is a solid turning into a liquid.

2) Evaporation is a liquid turning into a gas.

Question 6

What is the temperature like during the melting and boiling point of a liquid?

Answer 6

The temperature of a substance does not change while it is melting or boiling, even if it is still being heated.

Question 7

1) How does the density change when a substance is heated?

2) How does the density change when a substance cools down?

Answer 7

1) Substances expand when they are heated.

2) Substances contract when they cool down.

Question 8

What is drag?

Answer 8

Drag is another name for air resistance or water resistance. The amount of drag on something can be reduced by giving it a smooth surface and a streamlined shape.

Question 9

How can the pressure of gas in a container be increased?

Answer 9

— Putting more particles into the container (so there will be more collisions with the container walls each second).
— Heating the gas (so the particles move faster, hitting the walls harder and more often).
— Reducing the volume of the container (so the particles do not have as far to go between the walls and so collide with the walls more often).