calculations
dimensional homogeneity
each term in an equation, use to define a
physical process, should be expressed in same
units.
If units are different then the combination
should result in same unit, after applying
algebraic operations.
S equals v t plus half a t square
Combination become m equals m which is dimensionally
homogenous
Significant figures
A digit not used to show the position of the
decimal point is called a significant figure
5605
34.43
0.05892
500.0
All have four significant figures
There are two types of notation, scientific
vs engineering notation
Scientific notation requires just one digit
on left of decimal
Engineering Notation requires the exponent
of ten in order of three for prefixes.
Unit conversion
All units must be in either SI or FPS system
Some basic unit conversions are given here.
Rounding off numbers
There are three rules depending upon last
digit tell where we are rounding off. Let
n be the numbers we are rounding off to.
Either n plus oneth digit is less than 5
Or n plus oneth digit is equal to 5
Or n plus oneth digit is greater than 5
For digit less than 5, all other numbers are
dropped.
For digit equal to 5, the digit to left is
check and the number rounds up if odd and
rounds down if even. 1245 round to 3 digits
as third digit is even, the 5 will be dropped.
For 0.8655 round to 3 digits as third digit
is odd, the digit is rounded upped to 6.
For digit less than 5, the digit is rounded
up to next digit.
Pie, e or similar derived formulas are
accurate to infinite number of significant
figures
