Meaning & use
joules definition science
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Meanings
nouncountablephysics
A joule is the standard unit of energy in science, equal to the work done when a force of one newton moves an object one meter.
Grammar: Use 'joule' for one unit and 'joules' for more than one: one joule, five joules.
Patterns
- one joule
- measured in joules
- a joule of energy
The energy needed to lift an apple one meter is about one joule.
Scientists measure heat in joules, not in degrees.
A small battery might store thousands of joules.
nouncountablephysics
In everyday science lessons, a joule is a way to talk about how much energy something uses or produces.
Grammar: Often used after numbers or in phrases like 'per joule'.
Patterns
- per joule
- joules per second
- a few joules
The lamp uses about 60 joules every second.
A flash of lightning releases millions of joules.
The machine wastes energy, so each joule does less work.
Word forms
| plural | joules |
|---|
Common combinations
- measured in joules
- Energy is measured in joules in the SI system.
- joules per second
- One watt equals one joule per second.
- a joule of energy
- A joule of energy is quite small.
- convert to joules
- You must convert calories to joules for the calculation.
Synonyms and how they differ
- unit of energy
- A general phrase; 'joule' is the specific scientific unit.
Word family
Commonly confused: joules definition science or jewel? joules definition science or Jul?
joules definition science vs jewel
A jewel is a precious stone; a joule is a unit of energy. They sound similar but are unrelated.
joules definition science vs Jul
Jul is an abbreviation for July; joule is a scientific unit.
Practice
Which sentence uses 'joule' correctly?
Choose one answer.
A joule measures energy, so 'uses 100 joules per second' is correct. The other options confuse 'joule' with a food ingredient, a race, or a jewel.
Make it your own
Write a sentence using “joules definition science”, then check it and compare it with the examples above.