science

Wu (kana)

Wu (kana) is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Wu (kana) rather than just read about it. In short: Wu (hiragana: 𛄟, katakana: 𛄢) is a Japanese mora or a kana used to write it, though it has never been in standard use. History It is presumed that 𛄟 would have represented /β̞u/.

Key takeaways

Wu (kana) belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Wu (kana) to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Wu (kana) from memory before moving on to harder problems.

Reference excerpt

Wu (hiragana: 𛄟, katakana: 𛄢) is a Japanese mora or a kana used to write it, though it has never been in standard use.

History It is presumed that 𛄟 would have represented /β̞u/. Along with 𛀆 and 𛀁 (yi and ye respectively), the mora wu has no officially recognized kana, as these morae do not occur in native Japanese words; however, during the Meiji period, linguists almost unanimously agreed on the kana for yi, ye, and wu. 𛀆 and wu are thought to have never occurred as morae in Japanese, and 𛀁 was merged with え and エ.

Characters In the Edo period and the Meiji period, some Japanese linguists tried to separate kana u and kana wu. The shapes of characters differed with each linguist. 𛄟 and 𛄢 were just two of many shapes. They were phonetic symbols to fill in the blanks of the gojūon table, but Japanese people did not separate them in normal writing.

u Traditional kana う (Hiragana) 𛀋 (A variant form of う. Hiragana.) 𛀍 (A variant form of う. Hiragana.) ウ (Katakana) Constructed kana (A part of 傴. Katakana.) wu Traditional kana う (Hiragana) 𛀋 (A variant form of う. Hiragana.) ウ (Katakana) 𛄢 (An old variant form of ウ. Katakana.) Constructed kana ゔ(う with dots. Hiragana.) 𛄟 (A cursive script style of 汙. Hiragana.) (A cursive script style of 紆. Hiragana.) (A cursive script style of 迂. Hiragana,) (A cursive script style of 卯. Hiragana.) ヴ(ウ with dakuten. Katakana.) These suggestions were not accepted.

Unicode This kana has been encoded into Unicode 14.0 since September 14, 2021 as HIRAGANA LETTER ARCHAIC WU (U+1B11F), and KATAKANA LETTER ARCHAIC WU (U+1B122).

Notes

References

Illustrations

Worked examples

Example 1 — a first encounter with Wu (kana)

Start with the simplest possible case. Write down what Wu (kana) claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Wu (kana) before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Wu (kana) ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Wu (kana)

In research: Wu (kana) appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Wu (kana) in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Wu (kana) is common in secondary-school and first-year university syllabi. It links to neighbouring topics Specific kana, Writing system stubs, so understanding it makes those chapters shorter.
In everyday life: Look for Wu (kana) outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Wu (kana) in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Wu (kana) means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Wu (kana) out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Wu (kana) in simple terms?

Wu (hiragana: 𛄟, katakana: 𛄢) is a Japanese mora or a kana used to write it, though it has never been in standard use. History It is presumed that 𛄟 would have represented /β̞u/.

Why does Wu (kana) matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Wu (kana)?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Wu (kana).