Energy Efficiency

The Law of Conservation of Energy states:

• Energy can created or destroyed but not transformed

• Energy cannot be created or destroyed, it can only transformed

• Energy can't be created, destroyed or transformed

• Energy cannot be created or destroyed.

Tags

NGSS.MS-PS3-5

What kind of energy does an object possess when it's resting on top of the hill?

• Potential Energy

• Chemical Energy

• Kinetic Energy

• All of the above

Tags

NGSS.MS-PS3-2

A kettle uses 100J of electrical energy to produce 7J of sound energy and 93J of thermal energy. How efficient is the kettle?

• 100%

• 7%

• 93%

• 95%

A washing machine uses 250J of electrical energy to produce 125J of useful energy. How efficient is it?

• 5%

• 50%

• 55%

• 100%

What type of device might this Sankey be about?

• A very efficient LED light bulb
• A very inefficient incandescent light bulb
• A coal power plant
• A wind turbine

No machine in existence has 100% efficiency due to ____________________.

• magic
• friction
• smoke
• input

Tags

NGSS.MS-PS3-5

Total energy = 200J
Useful energy = 20J

Workout the efficiency of this lightbulb.
 $efficiency\ =\ \frac{useful\ enegy}{total\ energy\ in}\ \times100$  

• 100%

• 80%

• 40%

• 10%

To save energy, what should you do when you leave a room ?

• USE ELECTRICAL ENERGY

• SHUT OFF THE LIGHTS AND TELEVISION

• TURN ON THE LIGHTS AND TELEVISION

• HANG YOUR CLOTHES OUTSIDE

How can you dry your clothes to save energy?

• Use the dryer machine

• Don't dry your clothes

• Leave the fridge door open

• Hang the clothes to dry outside on a line

Tags

NGSS.MS-PS3-3

To increase the EFFICIENCY of energy use, we could...

• Turn off lights when not in use
• Keep the car running as you go into the store
• Water the plants in a drought

Tags

NGSS.MS-PS3-3