Introduction/ back to basics Flashcards
What is the repsective unit for Mass?
Dimensional symbol - M
Unit - kilogram (Kg)
What is the repsective unit for Length?
DImensional symbol - L
Unit - metre (m)
What is the repsective unit for Time?
Dimensional symbol - S
Unit- Second (s)
What is the repsective unit for force?
Dimensional symbol - F
Unit - Newton (N = m kg s-2)
How is force calculated?
Mass (m) x acceleration (a)
How many places will prefixes move the decimal point?
3 places
Apart from - deca, hecto, centi and deci
Is the symbol ever written as plural i.e., seconds?
NO
Are symbols lower case or upper case?
Lower case unless named after individual or larger than prefix of kilo (k)
How are units that are multiples of each shown?
Seperated by a space
m s = metres a second
ms = milliseconds
What does the expotent of unit with a prefix refer to?
Unit and prefix
KN2 = (KN)2 = KN x KN
How should physical constant and numbers with several digits on either side of the decimal point be written?
with a space between every 3 digits
95 959.599 995
How should numbers used in calculations interms of based or derived be expressed?
In terms of powers of 10 with expression as a final prefix
What is the exponentional of tera?
10*12
What is the exponentional of giga?
10*9
What is the exponentional of mega?
10*6
What is the exponentional of kilo?
10*3
What is the exponentional of deca?
10*1
What is the exponentional of deci, centi, milli, micro, nano and pico?
deci - 10-1
centi - 10-2
milli - 10-3
micro - 10-6
nano - 10-9
pico - 10-12
How are plane angular measuremenst expressed?
Radian (rad)
180* = pie rad
How should you convert units from smaller to larger and vice versa?
Going smaller multiply (m to cm multiply by 100)
Going larger (divide by conversion factor cm to m divide by 100)
What are natural number?
Counting number 1 2 3 4
WHat are integers?
positive and negative whole number
-5 -4 -3
5 4 3
What are rationals?
numbers that can be expressed as a ratio of 2 integers but can also be written as terminating or recurring decimals
What are some examples of rationals?
2/5= 0.4
What are irrationals?
numbers which cannot be expressed as either the ratio of 2 integers or recurring decimal
What is an example of an irrational?
square root 2 = 1.1442…
what is a + b?
sum of
what is a - b ?
difference between
What happens with a + a?
= 2a
What happens with a x a and a x a x a?
a2
a3
What happens with a x b?
ab (product of a and b)
What happens with -1 x a?
-a
What happens with 1/a?
a*-1 (reciprocal)
What are the numerator and denominator?
Num = top
Den = bottom
What is an example of cancelling a fraction to its simplest form?
2/6 = 1/3
What is needed to add/ subtract fractions?
denominator must be the same so must find the lowest common denomiator
What do you do if the denominator is different for adding?
7/16 = 3/8
double 3/8 =6/16
How do you multiply fractions?
Multiply numerators to give new numerator
Multiply denominators to give a new denominator
1/5 x 3/4 = 3/20
How do you divide a fraction?
flip the second fraction and multiply
1/2 / 3/4 = 1/2 x 4/3 =4/6
