The Physics of Water Flashcards
What are the three common states of matter of water?
Water is the only common, pure substance found naturally that exists a solid, liquid and gaseous form; all three common states of matter.
About how much of the Earth is covered with water?
About 70% of the Earth is covered with water, either as a liquid and in a solid matter.
Where is the majority of water found on Earth?
More water is found in the atmosphere as vapour than in the ocean itself.
What percent of the Earth’s water is fit for humans to drink?
About 97% of that water is in our oceans and only less than 1% of the remaining 3% is fit for humans to drink!
What are the chemical elements water is composed of?
Water is composed of the chemical elements Hydrogen and Oxygen (H20).
Many substances dissolve in water, therefore it is referred to universal solvent?
Many substances dissolve in water and it is commonly referred to as the universal solvent. Because of this, water in nature and in use is rarely pure/clean.
What has an effect on the temperature of water?
Pressure has an effect on temperature. If liquid is contained and put under pressure this normally increases the boiling point.
What is heat transfer?
Heat transfer is the passage of thermal energy from a hot to a cold body. It occurs in such a way that the object or fluid and the surroundings reach thermal equilibrium.
Can heat transfer be stopped?
Heat transfer can never be stopped; it can only be slowed down.
How much faster does water absorb heat (on average) than air?
Water absorbs heat (on average) 20 times faster than air. Water, in fact, has one of the highest heat capacities of all natural occurring substances.
Why is far more heat energy needed to heat water than air?
Far more heat energy is needed to heat water than air and this is due to the density of the molecules.
How much denser would air have to be to equal the density of salt water?
To equal the density of salt water air would have to be about 789 times denser.
What is conduction?
Conduction is the direct contact of the water, in which the diver causes heat transfer.
What is convection?
Convection is the movement of water across the diver carrying heat away. This can happen even if you are not moving relative to the water as in heating the water you cause it to become less dense and it rises only to be replaced by cooler water to repeat the cycle. This is called a convection current.
What is the main aim of a wetsuit?
The main aim of a wetsuit is to fit well and minimise water movement within it so to reduce the amount of heat lost through warming the cooler replacement water. This allows the diver to stay longer without becoming too cold.
