協力
きょうりょく · kyouryoku · JLPT N3 · noun
cooperation
🤝💪 協力 = join forces + power: strength pooled together
協 holds three 力 (power) beside 十 (ten, many): many hands adding their strength. Add another 力 and you get 協力, joining forces. Sound hook: kyou-ryoku, 'co-yoke-u': two oxen sharing one yoke.
力 — pictograph of a plow or arm muscle
力 originated as a pictograph of an ancient plow, the main tool requiring physical exertion in early agriculture. Some scholars also see it as a flexed arm showing muscle. From this concrete image it broadened to mean 'strength, power, force, effort'.