Mathematical Skills Flashcards
What is the speed of light?
3,00 x10^8 m.s^-1
What is the mass of an electron?
9,10 x10^-31 kg
What is scientific notation?
A way of representing numbers in a compact and consistent form
What is the format of scientific notation?
A single digit before the comma and two digits after the comma.
Multiplied by ten
With an exponent
If the number was small to start with, the exponent will be negative.
If the number was big to start with, the exponent will be positive
When converting numbers to scientific notation, how do you work out the exponent?
Move the comma so that it is after the first natural number value
Leave the next two digits after the comma, rounding off if you have to.
If you had to move the comma to the left, the exponent will be negative.
If you had to move the comma to the right, the exponent will be negative.
Count the number of “jumps” the comma made.
This will be the value of the exponent.
What are SI units?
A system of measurement used by scientists. All other units are derived from these.
How many SI units are there?
Seven
What do the seven SI units measure?
Length Time Mass Electric current Temperature Light intensity Amount of matter
What is the measurement for length?
Metre
What is the measurement for time?
Seconds
What is the measurement for mass?
Kilograms
What is the unit for electric current?
Ampere
What is the measurement for temperature?
Kelvin
What is the measurement for the amount of matter in an object?
Mole
What is the symbol for metre?
M
What is the symbol for second?
s
What is the symbol for kilogram?
kg
What is the symbol for Ampere?
A
What is the symbol for Kelvin?
K
What is the symbol for candela?
cd
What is the symbol for mole?
mol
What is the lowest measurement of temperature?
-273° K
Why is that the lowest temperature?
That is when atoms stop moving
What is the metric system?
A decimal system of units
In the metric system, how do units change in size?
By factors of 10
What are the ten main prefixes for sizes in the metric system?
pico nano micro milli centi deci kilo mega giga Tera
Which prefixes indicate the number is below the base unit?
pico nano micro milli centi deci
Which prefixes indicate the number is above the base unit?
kilo
Mega
Giga
Tera
What is the symbol for pico?
p
What is the symbol for nano?
n
What is the symbol for micro?
μ
What is the symbol for milli?
m
What is the symbol for centi?
c
What is the symbol for deci?
d
What is the symbol for kilo?
k
What exponent does pico indicate?
10^-12
What exponent does nano indicate?
10^-9
What exponent does micro indicate?
10^-6
What exponent does milli indicate?
10^-3
What exponent does centi indicate?
10^-2
What exponent does deci indicate?
10^-1
What exponent does kilo indicate?
10^3
How do you convert different measurements to the base unit?
Replace the prefix by its numerical value
How do you convert from a unit to another unit that is not the base unit?
Find the difference between the exponents belonging to those units.
Multiply the number by ten to the power of that difference
What happens when a unit is squared or cubed and you have to convert it?
The conversion factors must also be squared or cubed
What do you do when you have to convert from km per hour to m per s?
Divide your value by 3,6
How do you convert from m per s to km per hour?
Multiply by 3,6
Why is 3.6 used for this conversion?
km/h and m/s
To convert from m->km, x10^-3
To convert from h->s, x60x60
10^-3/3600 =3,6
How do you find unknown values in scientific formulae?
Substitute the data you have
Make the unknown value the subject of the formula
How do you make a variable the subject of a formula?
Get the variable on its own on the one side of the equation
What are the two types of relationships between variables in an experiment/formula?
Direct
Inverse
What is a directly proportional relationship?
When something happens to one side of the equation, the same thing happens to other side
What is an inversely proportional relationship?
When something happens to one side of the equation, the opposite will happen to the other
How do you recognise a directly proportional relationship in an experiment?
When the one value gets bigger or smaller, the same happens to the other value
How do you recognise an inversely proportional relationship in an experiment?
When the one value gets bigger or smaller, the opposite will happen to the other value.
What does a graph of a direct relationship look like?
A straight line increasing in height from left to right
What does a graph of an inverse relationship look like?
A curved line sloping down from left to right
What is a hypothesis?
An educated guess as to the outcome of the experiment
What does a hypothesis require?
It must be a statement
Independent variable
Dependent variable
Controlled variable
