APES Exam Math Review

Vocabulary flashcards for APES exam math review.

Percent Change Formula

((New Value - Old Value) / Old Value) * 100

Percent

Means per 100; divide by 100 to convert a percentage to a decimal.

Gross Primary Productivity (GPP)

The total amount of energy produced by producers in an ecosystem.

Respiration Loss (RL)

The amount of energy lost by producers due to respiration.

Net Primary Productivity (NPP)

GPP - RL; represents the energy available to consumers in an ecosystem.

Rule of Ten

In a trophic pyramid, only about 10% of the energy from one level is transferred to the next level.

Population Growth Rate Formula

((CBR - CDR) / 10)

Rule of 70

A method for estimating the doubling time of a population; doubling time = 70 / growth rate as a percentage.

Kilowatt Hour (kWh)

A unit of energy equal to 1,000 watts used over a period of one hour. Energy is the measure of power applied over time.

Half-life

The amount of time it takes for half of the initial mass of a radioactive element to decay.

Crude Death Rate (CDR)

The number of deaths per 1,000 individuals in a population per year.

CDR = \frac{Number \, of \, Deaths}{Total \, Population} * 1000

Half life

1. divide the amount of time over the half life

2. take the grams and divide them over 2 the amount of times found in step 1

Calculate half life using change in mass

1. Initial mass divided by 2 until you reach the final mass

2. divide the time period that theyre asking you to find out about by the half lives