2.10 Key Terms

Absolute zero: temperature at which all molecular motion ceases (at about [latex]−459\;^\circ\text{F}=−273\;^\circ\text{C}=0\text{ K}[/latex]) 2.4

Average speed [latex](V_{avg})[/latex]: is the distance traveled divided by the time during which the motion occurs. 2.5

Coefficient: the part of a number in scientific notation that is multiplied by a power of 10. 2.2

Exponent: the raised number to the right of the 10 indicating the number of factors of 10 in the original number. 2.2

Instantaneous speed: the speed at a specific instant in time. 2.5

Light-year: the distance that light travels during one year. 2.6

Metric system: system of measurement that has been adopted in virtually all countries except the United States and where every unit increases by a factor of ten. 2.4

Proportional: for ratios, if [latex]\frac{a}{b}[/latex] and [latex]\frac{c}{d}[/latex] are two ratios such that [latex]\frac{a}{b}=\frac{c}{d}[/latex] then the fractions are said to be proportional. 2.8

Ratio: a comparison of two numbers that can be written as: [latex]a[/latex] to [latex]b[/latex] OR [latex]a:b[/latex] OR the fraction [latex]a/b[/latex]. 2.8

Scientific notation is an expression of a number using powers of 10. 2.2

Standard notation is the straightforward expression of a number. 2.2

Speed is the rate at which an object changes its location. 2.5