Rank these machines by efficiency

Exercise and reference answers

Questions

1. A

   Electric motor

   B

   Coal power plant

   Higher value

   Electric motor

2. A

   Steam engine

   B

   Diesel engine

   Higher value

   Diesel engine

3. A

   Cycling and climbing

   B

   Swimming at the surface

   Higher value

   Cycling and climbing

4. A

   Solar cell

   B

   Residential gas heater

   Higher value

   Residential gas heater

5. A

   Weightlifting

   B

   Shoveling

   Higher value

   Weightlifting

6. A

   Gasoline engine

   B

   Nuclear power plant

   Higher value

   Nuclear power plant

Instructions

Tap the one in each pair with the higher efficiency, the share of input energy that does useful work.

Explanation