Mathematical Formulas

Question 1

Population density

Answer 1

Population
Area

Question 2

Rule of 70

Answer 2

70
Percent growth rate

Question 3

Population growth rate as a percent

Answer 3

((Births - Deaths) / Number of people) x 100

Question 4

Rate of change

Answer 4

(Final - Initial) / (Final time - Initial time)

Question 5

Percent Change

Answer 5

NOO times 100. ((New-old)/old) x 100

Question 6

Net Primary Productivity

Answer 6

GPP - RL

Question 7

GPP

Answer 7

total rate of photosynthesis by plants AKA total solar energy captured by plants - energy lost due to respiration by plants

Question 8

Fuel efficiency

Answer 8

distance traveled / unit of fuel consumed

Question 9

The 10% rule

Answer 9

states that roughly only 10% of energy transfers between trophic levels in a food chain, with the rest being lost as heat. To go up the energy pyramid, divide by 10. To go down the energy pyramid multiply by 10.

Question 10

Dimensional Analysis (unit conversion)

Answer 10

keep units on opposite sides of a division line to eliminate them

Question 11

Percent growth rate of a country

Answer 11

(CBR - CDR) / 10

Question 12

Kilowatt hours

Answer 12

measure electricity consumption.

Question 13

1 kwh

Answer 13

1000 watts of power used for one hour

Question 14

energy

Answer 14

power exerted over a period of time (power x time)

Question 15

LD50 (lethal dose)

Answer 15

dose/weight

Question 16

half life

Answer 16

amount of time (in years) that it takes for half of the mass of a radioactive element to decay

Question 17

half life calculation

Answer 17

amount remaining = original amount (0.5)^x
x = number of half lives

Question 18

Watt

Answer 18

Joule/sec

Question 19

Calorie

Answer 19

energy needed to raise one gram of water by one degree celsius

Question 20

British thermal unit

Answer 20

energy to raise one pound of water by one degree f

Question 21

kilowatts x hours

Answer 21

kilowatt hours

Question 22

efficiency

Answer 22

energy out/energy in