What is a Joule?

You've got a mother-in-law who's interested in what a electrical joule is? Wow! I guess there's no fooling her when you say,

"When there's no bulb in the socket, always keep the switch in the OFF position. It prevents the electricity from leaking out of the socket."

An electrical joule is equal to one watt-second. Just to make sure, I checked Wikipedia and got this which probably explains it better:

• The work required to move an electric charge of one coulomb through an electrical potential difference of one volt; or one coulomb volt, with the symbol C·V.
• The work done to produce power of one watt continuously for one second; or one watt second (compare kilowatt-hour), with the symbol W·s.

Joule is a unit of work. It is roughly the work you do when picking up a mango from the ground. The definition is that a Joule is the work done when a force of one Newton moves something through one meter distance. The weight of a mango is roughly a Newton (981 gms). When work is done at the rate of a Joule per second the power used is one Watt. Electric power is sold in Kilowatt hours. This is 36,00,000 Joules. I hope I have clarified your query.

The weight of a mango is roughly a Newton (981 gms).

If a mango weighs a Newton, its mass would be 101 grams. (That would be a rather small mango.) A very large mango, with a mass of 1 kg would weigh 9.81 Newtons.

You are right. I was wrong. While I was typing it out there were many distractions and I was not absolutely focused. This is what comes of multitasking! A new habit which is causing a lot of trouble. However that is no excuse for messing up such a simple thing. Sorry.

Joule is a unit of work done and is defined as the work done when a force of 1 Newton acts for a distance of 1 Meter.

Therefore, 1 Joule = 1 Newton-Meter

1 Newton is the force required to accelerate a mass of 1 Kilogram by 1 Meter / sec²

For example we know the acceleration due to gravity is 32.2 ft/sec² or 9.81 Meters/sec^2. Thus when we lift a mass of 1 Kg by 1 Meter we have done 9.81 Joules of work.

Power is work done per sec. Electrically a Watt of power is equal to 1 Joule per sec. A Kilowatt is 1000 watts and a Unit of electric consumption is Kilowatt-hour, that is to say, when 1000 watts of power is used for a duration of 1 hour, 1 Unit of Electric power has been consumed.

For the most basic definition,I should refer to a textbook,but here are practical definitions:

1)one Joule is the quantity of energy supplied by a power of one watt during one second.
Example:let's have a power supply of 5 volts,and a load resistor of 5 ohms.

The current into the load is 1 ampere,thus the power dissipated 5 watts,which provides 5joules during each second,e;g; 300 Joules during one minute and so on

2)one calory equal 4,18 Joules.

THus,the energy required to increase the temperature of 10 g of water,from 40°C to 50°C for example,the specific heat capacity being #1cal/g/°C,is:

10 x 10 calories, or 418 Joules.
Looking the reverse way,the energy of 1kg of boiling water versus a room temperature of 20°C is 1000 x 80 x 1 =80000calories =320kilojoules

The energy of ball lightning has been estimated to a few kilojoules.
For example,a lightning of 100kA under 1MV lasting 10µs carries an energy of:

1E5 x 1E6 x 1E-5 = 1megajoule

3)last,the energy of a photon,the quantum of energy of the electromagnetic field, is related to the frequency of the electromagnetic field with the PLanck constant: E = h F with h=6,64 E-34 Joule second

and F in Hertz (1/second)

F is 1E5 to 1E11 Hertz for radio waves, 1E12 to 1E14 for infra-red,1E15 for visible light,then X rays and gamma rays up to 1E19Hertz and more.

Yes you are absolutely right. (about sounding stupid), It would have taken you less time to google it, than to read all of these knowledgeable answers.

1 joule = 1 Watt per 1 Second.

Wangito.

Oh, by the way, I think your mother-in-law was trying to tell you something, Joule is also: power over time= Work...

a joule is a standard unit of energy in general scientific applications. U can search it through WWW. Google.com It is used as a unit in the International System, just search google