8I Fluids Flashcards
What are the three states of matter?
Soild, liquid and gas.
What happens to the temperature of a substance when it is changing state?
E.g. solid to liquid
The temperature stays constant.
What happens to the pressure on a diver as she gets deeper?
The pressure increases with depth.
Explain what causes pressure in a balloon.
The air particles in the balloon collide with the walls and exert a force on them.
What equation is used to calculate density?
Density = mass/volume
What is drag?
Drag is the friction caused by moving through a fluid.
E.g in air it’s called air resistance, in water it’s called drag.
If an object has a mass of 150 g and a volume of 30 cm3 , what is its density?
Density = mass/volume
density = 150/30 = 5 g/cm3
What is the change of state from gas to liquid called?
Condensation.
An object with a density of 4g/cm3 is placed in a bowl of water. What happens to it?
Water has a density of 1g/cm3 so the object will sink as it is denser than water.
What happens to an object with a density of 0.75 g/cm3 when it is placed in a bowl of water?
It will float as it is less dense than water which has a density of 1 g/cm3.
Describe what happens to atmospheric pressure as you climb a mountain?
The atmospheric pressure decreases with increasing altitude.
Calculate the density of an object with a mass of 64 kg and a volume of 8 m3.
Density = mass/volume
Density = 64/8 = 8 kg/m3
What is the change of state from solid to liquid called?
Melting.
What is the change of state from liquid to gas called?
Evaporation.
What is the change of state from liquid to solid called?
Freezing.
What happens to the pressure in a sealed container of gas when it is heated?
The pressure increases because the gas partcles hit the container walls more often and with greater energy, because they are moving faster.
What is happening where the graph is horizontal?
The substance is changing state;
first - from solid to liquid
second - liquid to gas
Why does an inflated balloon shrink if you leave it in the freezer?
The pressure drops because the gas particles move more slowly and hit the walls
of the balloon less often and with less energy.
