Energy Math

A 2000W electric space heater was used for 3 hours and 30 minutes. How much energy did the heater use?

• 2000W

• 7000kWh

• 7kWh

• 2kWh

• 6500kWh

Fremont, with a population of 300,000 people, uses 8million Btu of energy each day. The yearly per capita energy consumption in the city is nearest to

• 10,000BTU

• 1,000,000Btu

• 10,000,000Btu

• 1,000,000,000Btu

• 10,000,000,000Btu

Tags

NGSS.MS-PS3-5

If a 100 W incandescent bulb uses 400 kJ of energy per hour. How much would a CFL use that is 3 times as efficient IN 30 MINUTES?

• 66 kJ

• 133 kJ

• 200 kJ

• 1200 kJ

One gallon of fuel produces 5 lbs of CO2. Two cars drive 100 miles each. The first gets 10 MPG. The second gets 25 MPG. How much LESS CO2 is produced by the second car?

• 10 pounds

• 50 pounds

• 30 pounds 

• 15 pounds

Tags

NGSS.MS-PS3-5

If the capacity of a power plant is 1,000 MW and its capacity factor is 0.9, how much energy in MWh can the power plant produce in 1 day?

• 27,000 MWh

• 26,700 MWh

• 21,600 MWh

• 2,160 MWh

Tags

NGSS.HS-PS3-3

How is the efficiency of a device calculated?

• (useful energy out divided by total energy in ) x 100

• (useful energy out x by total energy in ) x 100

• (useful energy in divided by total energy out ) x 100

• (useful energy x divided by total energy in )divided by 100

Tags

NGSS.MS-PS3-3

How many cubic feet of natural gas do the 5,100 homes of Tichigan currently consume in one year?

• 5,100,000 ft³

• 25,500,000 ft³

• 1,000,000 ft³

• 6,120,000 ft³

Tichigan is a rural community in Wisconsin with a population of 5,100 homes. It gets its heat energy from natural gas. The average home consumes 1,000 cubic feet of natural gas per year. Residents of Tichigan pay the utility $0.05 per cubic foot of gas.

How much does the town need to pay for all its energy?

• $255,000

• $500,000

• $205,000

• $155,000

A family is building a new home in Chattanooga, TN. Assume the following conditions are true:

* The house has 3500 square feet

* 100,000 BTUs of heat per square foot are required to heat the house for the winter

* One cubic foot of natural gas supplies 1000 BTUs of heat energy.

* Natural gas sells for $0.03 per cubic foot

What is the total amount of energy (BTUs) needed to heat the house for winter?

• 350,000,000 BTUs

• 100,000,000 BTUs

• 30,000,000 BTUs

• 3,500,000 BTUs

A family is building a new home in Chattanooga, TN. Assume the following conditions are true:

* The house has 3500 square feet

* 100,000 BTUs of heat per square foot are required to heat the house for the winter

* One cubic foot of natural gas supplies 1000 BTUs of heat energy.

* Natural gas sells for $0.03 per cubic foot

What is the number of cubic feet of natural gas required to heat the house for the winter?

• 350,000 ft³

• 100,000 ft³

• 30,000 ft³

• 3,500 ft³

Tags

NGSS.MS-PS3-4