Efficiency

• Natuurkunde
• Middelbare school
• havo, vwo
• Leerjaar 2,3

Efficiency

Textboek

Nova 3 HV TTO 2019-2020

commitments

classroom

idoceo

bookwidgets

Gmail

Gdrive

badges

help

You know how to draw and use an energy flowchart

You can make calculations using the concept of efficiency

Energy flowchart

Efficiency

In this example the efficiency will be calculated as follows:

​40J​​8J​​

x 100 % = 20 %

I often use 

a table to make a quick calculation

Efficiency is about the amount of energy which is used usefully compared to the total amount of energy you put into everything.

Sustainable energy

Replacing incandescent light bulbs with energy saving light bulbs will save you a lot of energy (and money).

Both lamps will convert 3 Joule of electric energy every second into light (3 W). 

But since the efficiency of the energy saving light bulb is much larger, it needs less total energy to produce the same amount of light (5 times less).

Calculate the efficiency

Calculate the efficiency

Calculate the efficiency

3,8 J of 6,5 J energy is converted into light in a lightbulb. What is the efficiency of the lightbulb?

1. 171%
2. 58%
3. 37%
4. 15%

Tip

You can use flowcharts to think about the usefull Energy needed for heating up the house. This will be constant regardless of the type of heater used.

Upload your solution
to the last assignment