浮力
fú lì · HSK 7
buoyancy
🛟 浮 (float) + 力 (force) = floating force = buoyancy
浮 fú means to float on water; 力 lì means force or power. Together: the upward force that makes things float. Same 力 appears in 努力 (effort) and 电力 (electric power).
浮 — water radical 氵 + 孚 (phonetic, 'hatch/trust')
浮 is a semantic-phonetic compound. The water radical 氵 gives the meaning 'water,' while 孚 supplies the sound and originally depicted a bird hatching an egg. Together they convey something resting on water, hence 'to float.'
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'.