APES Formulas

What is the formula for energy efficiency?

Efficiency = (Useful Output Energy / Total Input Energy) × 100

What is the rule of 10 for trophic levels?

Only about 10% of energy is transferred to the next trophic level

How do you calculate birth rate?

Birth Rate = (Births / Total Population) × 100

How do you calculate death rate?

Death Rate = (Deaths / Total Population) × 100

How do you find population growth rate?

Growth Rate (%) = (Birth Rate - Death Rate) / 10

What is the formula for doubling time?

Doubling Time = 70 / Growth Rate (%)

What is the formula for percent change?

Percent Change = ((New - Original) / Original) × 100

How do you calculate population density?

Population Density = Population / Area

What is the formula for NPP?

NPP = GPP - Respiration

How do you calculate power?

Power (W) = Energy (Joules) / Time (seconds)

How do you calculate energy usage?

Energy = Power × Time

How do you convert kWh to Joules?

1 kWh = 3.6 × 10^6 Joules

How do you calculate cost of electricity?

Cost = Power (kW) × Time (hours) × Rate ($/kWh)

What is the formula for ppm?

ppm = (mass of solute / mass of solution) × 1