SI units, measurements and physical quantities GapFill

In any experiment, there will be errors in the final result.
Errors which have an effect of different magnitudes and in different directions for each result around the mean are  percentage errorsabsolute errorsrandom errorssystematic errors. This can be due to the changing conditions in the laboratory, or from human error.
Errors which have effects which are always the same magnitude and in the same direction are  percentage errorsabsolute errorsrandom errorssystematic errors. This can be due to a problem with the equipment, or not calibrating the equipment correctly. A calibration error is also known as a  percentage errorsystematic errorabsolute errorzero error.
A data set that is all very close to a single value is said to have high  accuracyprecisionuncertaintyresolution.
A data set that has a mean close to the expected or 'true' value of the experiment is said to have high  uncertaintyresolutionprecisionaccuracy.
An experiment that produces similar results each time it is performed by the same researcher using the same equipment is said to have high  repeatabilityuncertaintyreproducibilityresolution.
An experiment that produces the same results when repeated using different equipment and/or researchers is said to have high  resolutionreproducibilityuncertaintyrepeatability.
A piece of equipment that allows a reading to be taken within a small range of uncertainty is said to have a high  resolutionprecisionaccuracyuncertainty.
All quantities can be described as either scalars or vectors. Scalars are quantities with  no unitsmagnitude and sizemagnitude but no directionmagnitude and direction, while vectors are quantities with  magnitude and sizemagnitude but no directionmagnitude and directionunits.
Vectors can be resolved in components. To find the size of the vertical component of a vector, the equation  v × sin(θ)θ × cos(v)v × cos(θ)θ × sin(v) can be used, and to find the horizontal component, the equation  v × sin(θ)θ × sin(v)θ × cos(v)v × cos(θ) can be used, where θ is the angle between the horizontal and the vector and v is the size of the vector.
To find the size and angle of a vector from its components, use  √(v(x)² + v(y)²)v(x) × v(y)v(x) ÷ v(y)√(v(x) + v(y)) to find its size, and  θ = cos(v(y)) + sin(v(x))tan(θ) = v(y) ÷ v(x)√(v(x)² + v(y)²)tan(θ) = v(y) × v(x) to find its angle.