LESSON 3 SCIENTIFIC NOTATION

Graphs

• provide a visual representation of data and a better form of communication than tables of data.

• creating and interpreting it, is an essential skill in the sciences, especially in physics where relationships between variables need to be derived.

Direct Variation, Inverse Variation, Parabolic Relationship

types of graph

Direct Variation

• exists between any two variables when one quantity is directly dependent on the other.

• It is the relationship between two variables where one of the variables is a constant multiple of the other.

Directly Proportional

the two variables are directly related to each other

Inverse Variation

• is another way of describing a relationship between two variables.

• means that as one variable increases, the other one decreases. 

Parabolic Relationship

• The value of the dependent variable is proportional to the square of the independent variable.

• the general equation defining this type of relationship or function is y = kx² where k is a numerical constant that remains the same as x and y change respectively.

error in measurements

• is defined as the difference between the true, or accepted value of a quantity and its measured value.

• It is a way of expressing accuracy, or how close a measurement is to the “true” value.

systematic error

errors resulting from measuring devices being out of calibration (instrumental) or sometimes caused by external conditions (wind, temperature, humidity and vibrations).

random error

errors resulting in the fluctuation of measurements of the same quantity about the average. The measurements are equally probable of being too large or too small. It is also called chance error or statistical error.

personal error

• are caused by carelessness, poor technique, or bias in readings, recording, or calculations.

• should be avoided and corrected if discovered.

absolute error

is always expressed with the units of the quantity being measured. 

relative error

can be expressed as either a fraction of the measured quantity or as a percentage, with the latter as the most  common

significant errors or significant digits

• are the digits in a number that carry meaningful information about its precision.

• They reflect the accuracy of a measurement or calculation. More significant figures mean higher precision.