Physics - Quantities and Measurement

Define systematic error

A systematic error will result in ALL readings having a CONSTANT error is ONE direction

Define random error

A random error will result in a SCATTER of reading about a mean value

Define accuracy

Accuracy is the degree to which a measurement approaches the true value

Define precision

Precision is the degree of agreement of repeated measurements of the same quantity

How can you deduce random error and systematic error graphically?

Random error: the data points are SCATTERED on both sides of the line of best fit

Systematic error: the best fit line does not pass through the origin

How does drawing a line of best fit help reduce random error?

The best fit line balances the deviations of the data points on either side of the line, reducing the effects of random errors.

State two ways in which an equation is dimensionally consistent but physically incorrect

1: The equations may have missing or extra terms

2: The equations may have incorrect coefficients

Define a scalar quantity

A scalar quantity is a quantity that has MAGNITUDE only, not direction

Define a vector quantity

A vector quantity is a quantity that has BOTH magnitude and direction

What is a homogeneous equation?

A homogeneous equation is one whereby EVERY TERM in the equation has the SAME UNIT

Must a homogeneous equation be physically correct?

No. A homogeneous equation may not be physically correct. HOWEVER, a physically correct equation MUST be homogenous as it is confirmed experimentally

Note: an inhomogeneous equation is DEFINITELY physically incorrect.