Worksheet 5 . energy efficency

The law of conservation of energy states that when one form of energy is converted into another,

• energy is destroyed in the process
• no energy is destroyed in the process
• energy is created in the process
• some amount of energy cannot be accounted for

In energy transformations, "wasted energy" usually takes what form?

• heat
• chemical energy
• light
• sound waves

Efficiency is calculated by useful energy output divided by total energy input, expressed as a percentage

• False

• True

The flow of electrical power

• Energy

• Wiring

• Electrical Energy

• Energy Conservation

Energy is…

• An action that results in using less energy

• The ability to do work or make a change

• Thunder

• the energy of motion

The energy of motion

• Gravitational Energy

• Kinetic Energy

• Mechanical Energy

• Legs

What is the efficiency of a machine if 55.3 J of work are done on the machine, but only 14.3 J or work are done by the machine?

• 0.25 Joules
• 26%
• 3.86 Joules
• 386%

• 100%

• 80%

• 40%

• 10%

• 100%

• 80%

• 40%

• 20%

• 100%

• 10%

• 40%

• 20%