An automobile engine gives 35,000 BTUs of mechanical energy from 100,000 BTUs of fuel. The transmission, axles and tires deliver 30,000 BTUs of mechanical energy to the highway, moving the car forward. What is the overall efficiency of this vehicle?

An automobile engine gives 35,000 BTUs of mechanical energy from 100,000 BTUs of fuel. The transmission, axles and tires deliver 30,000 BTUs of mechanical energy to the highway, moving the car forward. What is the overall efficiency of this vehicle?

Answer: 30%

In a car, the non-useful, waste energy output is in the form of __________ energy.

In a car, the non-useful, waste energy output is in the form of __________ energy.

Answer: thermal/heat

Which energy conversion device typically has the lowest energy efficiency?

Which energy conversion device typically has the lowest energy efficiency?

Answer: automobile engine

The potential energy stored in the bonds that hold molecules together is called ________ energy.

The potential energy stored in the bonds that hold molecules together is called ________ energy.

Answer: chemical

Energy demand is a/an

Energy demand is a/an

Answer: exponential function - longer it goes, the more rapidly it grows

If the energy input of a system is 200 calories and its useful output is 36 calories, what is the efficiency of the system?

If the energy input of a system is 200 calories and its useful output is 36 calories, what is the efficiency of the system?

Answer: 0.18

The useful output from a heat engine is 962 joules. The energy that is wasted is 4428 J? What is the efficiency of the engine?

The useful output from a heat engine is 962 joules. The energy that is wasted is 4428 J? What is the efficiency of the engine?

Answer: 0.1784

A watt is a unit of?

A watt is a unit of?

Answer: power

Worldwide, we expect the use of which energy resource to decrease over the next 20 years?

Worldwide, we expect the use of which energy resource to decrease over the next 20 years?

A) Nuclear
B) Coal
C) Hydroelectric


Answer: NONE

In a light bulb, the non-useful, waste energy output is in the form of __________ energy.

In a light bulb, the non-useful, waste energy output is in the form of __________ energy.

Answer: thermal/heat

In the process of mining coal, the useful energy output is in the form of __________ energy.

In the process of mining coal, the useful energy output is in the form of __________ energy.

Answer: chemical

21 million Joules of chemical energy are supplied to a boiler in a power plant. 5,000,000 Joules of energy are lost up the smokestack. The boiler radiates 1.5 million Joules of heat to the atmosphere. What is the efficiency of the boiler?

21 million Joules of chemical energy are supplied to a boiler in a power plant. 5,000,000 Joules of energy are lost up the smokestack. The boiler radiates 1.5 million Joules of heat to the atmosphere. What is the efficiency of the boiler?

Answer: 0.690

In a car, the useful energy output is in the form of _____ energy.

In a car, the useful energy output is in the form of _____ energy.

Answer: mechanical

Which primary energy resource contributes the most to the production of electricity in the US?

Which primary energy resource contributes the most to the production of electricity in the US?

Answer: coal

Three energy conversion processes take place in succession. The first has an efficiency of 51%, the second is 50% efficient, and the third 10%. What is the efficiency of the entire process?

Three energy conversion processes take place in succession. The first has an efficiency of 51%, the second is 50% efficient, and the third 10%. What is the efficiency of the entire process?

Answer: 0.0255

What is doubling time?

What is doubling time?

Answer: time during which the initial quantity increases by a factor of two

Large energy companies have drilled thousands of wells to exploit the Marcellus Shale formation. A Pennsylvania motel operator finds that her previously struggling motel is suddenly fully booked most of the time with people who are working for these natural gas operations. This is an example of

Large energy companies have drilled thousands of wells to exploit the Marcellus Shale formation. A Pennsylvania motel operator finds that her previously struggling motel is suddenly fully booked most of the time with people who are working for these natural gas operations. This is an example of

Answer: an externality

The quantity of an energy source that is known to exist and that can be economically recovered is called?

The quantity of an energy source that is known to exist and that can be economically recovered is called?

Answer: reserve

When analyzing how much energy is required to produce an energy product, e.g. ethanol from corn, we are talking about?

When analyzing how much energy is required to produce an energy product, e.g. ethanol from corn, we are talking about?

Answer: energy return on energy invested-EROI

If the world demand for energy is growing at the rate of 10% per year, when would we expect the energy demand to be twice today's?

If the world demand for energy is growing at the rate of 10% per year, when would we expect the energy demand to be twice today's?

Answer: 7 years