努力 (nǔ lì)

to make an effort; to try hard; to strive; hard-working; conscientious

Character breakdown

努 (nǔ) · 7 strokes

Phonosemantic compound. 力 represents the meaning and 奴 represents the sound.
力 (Lì) · 2 strokes

Pictograph of a plow, which requires strength to operate.