Energy Efficiency Calculations

Energy efficiency =

• power x time to boil

• final temperature - initial temperature

• 4.2 x volume of water x change in temperature

• useful energy / input energy x 100

Energy efficiency should be expressed as....

• Joules

• Grams

• Watts

• %

The efficiency of this light bulb is

• 40 %

• 60 %

• 100 %

• 1.67 %

• 0.0167 %

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-4

The Russell and Hobbs kettle had a starting temperature of 24 degrees and a final temperature of 100 degrees. The power of this kettle is 2400 watts. It took 84 seconds to boil. 500mL of water was boiled. CALCULATE THE INPUPT ENERGY

Tags

NGSS.MS-PS3-4

NGSS.MS-PS3-5

The percent of energy that is used for work

• Energy efficiency

• Renewable energy

• Nonrenewable energy

• Combustion

Tags

NGSS.MS-PS3-5

Which of the following is an example of energy efficiency?

• A light bulb that converts 90% of electrical energy into light

• A car engine that converts 30% of fuel energy into motion

• A heater that converts 50% of electrical energy into heat

• A solar panel that converts 20% of sunlight into electricity

the percentage of energy put into a system that does useful work.

• Energy Conservation

• Energy Efficiency

• Energy Wattage

• Electricity

Tags

NGSS.HS-PS3-3

The percentage of energy put into a system that does useful work is:   

• energy conservation

• renewable energy

• energy efficiency

• energy conversion

Tags

NGSS.HS-PS3-3

NGSS.HS-PS3-4

The Russell and Hobbs kettle had a starting temperature of 24 degrees and a final temperature of 100 degrees. The power of this kettle is 2400 watts. It took 84 seconds to boil. 500mL of water was boiled.. CALCULATE THE EFFICIENCY AS A PERCENTAGE

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-3

NGSS.MS-PS3-4

NGSS.MS-PS3-5

Energy efficiency is...

• How well a device converts input energy into useful energy

• Energy that is not used for something useful/ something we want

• Energy that is used for something useful

• Energy that goes into a device/ process

Tags

NGSS.MS-ETS1-4