July (unit)

format_list_bulleted Contenido keyboard_arrow_down

ImprimirCitar

The July or joule (English pronunciation: /ˈdʒuːl/; symbol: J) is the unit derived from the International System used to measure energy, work, and heat. As a unit of work, the joule is defined as the amount of work done by a constant force of one newton over a meter of length in the same direction of the force.

In this definition, being so specific, types of resistance such as air friction are not considered.

Its symbol is J, with a capital letter and no period, like all symbols for SI units derived from personal names.

The unit joule can also be defined as:

The work necessary to move a load of an assmbie through a voltage (potential difference) of a volt. I mean, a voltio-culombio (V·C). This relationship can be used, in turn, to define the volt unit.
The work necessary to produce a watt of power for a second. I mean, a watt-second (W·s). This relationship is also usable to define the watt.

It can be used to measure heat, which is kinetic energy (motion in the form of vibrations) at the atomic and molecular scale of a body.

It is named after the English physicist James Prescott Joule (1818–1889).

Equivalences

The July is equal to:

${mathrm {1,J=1,Ncdot m=left(kgcdot {frac {m}{s^{2}}}right)cdot m={frac {kgcdot m^{2}}{s^{2}}}}}$

Where N represents newtons; m, meters; kg: kilograms; s: seconds.

One July equals: 1 N·m (newton·meter); 1 W·s (watt·second); 6,2415 × 10¹⁸ eV (electronvoltio); 1 C·V (culombio·voltio); 0.00987 atm·L (atmosphere·litro); 1 Pa·m3; 0.238902957 cal (heating)

Reverse equity: 1 Wh (watt-hour) = 3600 J; 1 kWh (kilowatt-hour) = 3.6·10⁶ J = 3.6 MJ; 1 cal (heating) = 4,187 J; 1 kcal (kilocalorie) = 1000 cal = 4187 J; 1 tep (oil equivalent ton) = 41,84·10⁹ J = 11 622 kilowatt hours; 1 tec (carbon equivalent tone) = 29.3·10⁹ J = 8138.9 kilowatt-hour; 1 g TNT = 4184 J ≈ 1 kcal

Approximate practical equivalencies

To get an idea of the magnitude of a joule, there are several examples in everyday life that can give some idea of that amount of energy. One joule is approximately the:

Energy needed to throw a small apple a metre up.
Energy released when a small apple falls one meter to the ground.
Energy released by a resting person in a hundredth of a second.
Cynetic energy (movement) of a 56 gram tennis ball at 22 km/h or 6 m/s.
Cynetic energy of an adult human moving at a speed of about 20 cm/s.
Energy required to raise 0.24 °C the temperature of a gram of water.

Multiples of the SI

The following is a table of the multiples and submultiples of the International System of Units.

International System Multiples for July (J)
Value	Symbol	Name	Value	Symbol	Name
Submultiplos			Multiple
10⁻¹ J	dJ	decijullation	10¹ J	daJ	decajulio
10⁻² J	cJ	centijulio	10² J	hJ	hectojulio
10⁻³ J	mJ	milijulio	10³ J	kJ	kilojulio
10⁻⁶ J	μJ	microjulio	10⁶ J	MJ	megajudge
10⁻⁹ J	nJ	nanojury	10⁹ J	GJ	gigajulio
10⁻¹² J	pJ	picojulio	10¹² J	TJ	terajulio
10⁻¹⁵ J	fJ	femtojulio	10¹⁵ J	PJ	petajulio
10⁻¹⁸ J	aJ	attojulio	10¹⁸ J	EJ	exajulio
10⁻²¹ J	zJ	zeptojulio	10²¹ J	ZJ	zettajulio
10⁻²⁴ J	yJ	yoctojulio	10²⁴ J	YJ	Yottajulio
10⁻²⁷ J	rJ	reddish	10²⁷ J	RJ	ronnajulio
10⁻³⁰ J	qJ	Quectojulio	10³⁰ J	QJ	quettajulio
The most common prefixes of the unit are in bold.

This unity of the International System is named in honor of James Prescott Joule. In the units of the SI whose name comes from a person's own name, the first letter of the symbol is written with capital (J), while his name always starts with a tiny letter (July o joule), except in case you start a sentence or a title.
Based on The International System of UnitsSection 5.2.

Order of magnitude

Main article: Annex: Orders of magnitude (energy)

The joule is a very small unit of energy for ordinary life. Approximately one joule is the amount of energy required to lift 0.1 kg a height of 1 meter on the earth's surface. A kick from an athlete can have an energy of about 200 J; a 20 W bulb (of any type) burning for 8 hours expends about 600,000 J; and the electricity consumption of an average family during a month can be 1,000,000,000 J (about 278 kWh).

Contenido relacionado

Más resultados...