Fire Science

Question 1

Velocity of Water

Answer 1

d²

Question 2

Discharge of Water

Answer 2

20

Question 3

Jet Reaction

Answer 3

   10

Question 4

Capacity of a Hoseline

Answer 4

10,000

Question 5

Discharge through nozzle

Answer 5

3

Question 6

Loss of Pressure due to friction

Answer 6

    d⁵

Question 7

Water Power

Answer 7

 60

Question 8

Efficiency of Pump

Answer 8

WP
—- x 100
BP

Question 9

Quantity of Water

Answer 9

V x A

Question 9

Define Liquids of Different Density

Answer 9

Whether a liquid will rest on top of another for example petrol on water, thus determining which firefighting extinguishing media to use

Question 10

Define gases of different density

Answer 10

Whether gas will rise or fall in air. This could lead you to where a leak of a substance is collecting

Question 11

What is density ?

Answer 11

Density of a material in defined as the mass of one cubic metre of material. To calculate density is D = mass/volume

If the mass is kg and the volume is cubic metres density is kg/cm3

If mass is grams and the volumes is cm, density is g/cm3

If the figure is lower than 1 it floats, if it’s higher that 1 it sinks

Question 12

What is relative density

Answer 12

Also known as specific gravity (gravity)

The ratio of the mass of any volume of it to the mass of an equal amount of water.

Relative Density =. Mass of any volume of the substance
Mass of an equal volume of water

No units involved.

Question 13

What is vapour density?

Answer 13

The measure of density of a vapour or a gas in relation to equal amounts of hydrogen. Air is also sometimes used as a measure as you will be able to see whether it rises or falls in normal conditions.

Question 14

What is matter

Answer 14

It exists in 3 states. Solid Liquid and Gas

Question 15

What are atoms?

Answer 15

Atoms are tiny particles that are too small to see. Everything is made of atoms, there different types of atoms, these are called elements, the elements all have different symbols.

Question 16

What are molecules?

Answer 16

Molecules are atoms chemically bound together.

Question 17

Discuss elements.

Answer 17

Elements contain only 1 sort of atom either alone or grouped into molecules containing 1 type of atom.

Question 18

What are Compounds?

Answer 18

Compounds are formed from only 1 type of molecule which contains more than 1 kind of atom

Question 19

What is a mixture

Answer 19

Mixtures contain more than 1 kind of molecule.

Question 20

Describe an Atom

Answer 20

Atoms have a central core or nucleus which contains smaller particles called protons and neutrons. Protons have a positive charge. The nucleus is surrounded by a system of electrons which each carry a negative electrical charge. Atoms contain as many electrons as protons. This means they are neutral.

Greek for indivisible, until about 70years ago, Greeks believed that atoms could not be split. We now know that atoms of one element can be ‘split’ or combined with other particles to make new atoms of other elements.

Question 21

What is energy

Answer 21

Energy is expended in doing work and may be in one of a number of different forms heat, light and electrical energy, potential and kinetic

Question 22

What is potential energy

Answer 22

Possessed by a body due to its position

Question 23

What is kinetic energy

Answer 23

Possessed by a moving body

Question 24

What is an element

Answer 24

An element is a substance which contains atoms which are all of the same type: they all have the same number of protons. As there are can be anything up to just over 92 protons in an atom, there are just 92 stable elements. Atoms of different elements can combine to form molecules.

Question 25

Discus compounds

Answer 25

Some molecules consists of two or more atoms of the same kind: for example, an oxygen molecule consists of two oxygen atoms (O2). Other molecules consist of two or more atoms of different kinds: carbon dioxide consists of two atoms of oxygen and one of carbon (CO2), water consists of two hydrogen atoms and one oxygen (H2O). Carbon dioxide and water are chemical compounds and they can, by chemical means, be split into their component elements.

Question 26

What is temperature ?

Answer 26

Temperature is a measure of how hot something is and is related to how fast the constituent molecules are moving.