If a population grows at a rate of 8.5%, how long will it take that population to double?

If an incandescent light bulb used for lighting has an efficiency rating of 5%, then for every 1.00 joule of electric energy consumed by the bulb, which of the following is produced?

Based on the data in the graph, by approximately what percent did the sea ice decrease from 1980 to 2005 ?

Sugar beets have a gross primary productivity (GPP) of 160 g/m2/day. They have a respiration rate of 25%. What is their net primary productivity?

The combustion of one gallon of automobile fuel produces about 5 pounds of carbon (in CO2). Two autos are making a trip of 600 miles. The first auto gets 20 miles per gallon, the second gets 30 miles per gallon. Approximately how much LESS carbon (in CO2) will be produced by the second automobile on this trip?

If a population grows at a rate of 3%, how long will it take that population to double?

The net annual primary productivity of a particular wetland ecosystem is found to be 8,000 kcal/m2 per year. If respiration by the aquatic producers is 12,000 kcal/m2 per year, what is the gross annual primary productivity for this ecosystem, in kcal/m2 per year?

Energy flow in Lake Fremont (kcal/m2/year

Trophic level Energy Consumed Waste Energy GPP NPP

Producers --- 1,500,000 10,000 8,000

Primary Consumers 2,000 1,600 200 180

Secondary Consumers 160 100 40 10

In the community described above, which of the following represents the respiratory energy (kcal/m2/year) used by autotrophs?

The half-life of radon gas is approximately four days. Four weeks after the introduction of radon into a sealed room, the fraction of the original amount remaining is closest to

What is the scientific notation of the following number: 5,689,000,000

If gross primary productivity in a wetland is 3 kg C/m²/year and respiration is 1.5 kg C/m²/year, what is the net Primary Productivity of the wetland?

In 2000, the level of ammonia in a river was 63ppm. In 2004, the level was 112ppm. what is the percent increase since 2000?

What is the percent change: 234.98 to 324.77

Burning one gallon of gasoline in a car releases approximately 20 pounds of CO2 into the atmosphere. One person drives 60,000 miles in a car that averages 30 miles per gallon (mpg), while another person drives 60,000 miles in a car that averages 20 mpg. Over the course of the 60,000 miles, how many fewer pounds of CO2 are released by the 30 mpg car than by the 20 mpg car?

1 meter = 1.094 yards

How many meters are in 5 yards?

If a city with a population 10,000 experiences 100 births, 40 deaths, 10 immigrants, and 30 emigrants in the course of a year, what is its net annual percentage growth rate?

The Chernobyl nuclear disaster led to the release of massive radiation, specifically iodine-131 and cesium-137, which has been connected to a variety of environmental problems in the 30 years following the disaster. A soil sample near Chernobyl was found to contain 187 kBq/m2 of cesium-137. If the half-life of cesium-137 is approximately 30 years, how much cesium-137 will remain in the sample after 90 years?

If a population of a country grows at a rate of approx 5 percent per year, the number of years required for the population to double is closest to

If the population of a country is growing at a rate of 1.75 percent per year, the population will double in approximately how many years?