ちからまかせ (chikaramakase)
* “J-WOTD” = “Japanese Word of the Day”
“do something in an angry state” (not sure about this… some Japanese person, please leave a comment?)
子どもが親に怒って庭で力任せにボールを蹴り続けていました
The kid was angry with his parents, and just kicked the ball for hours in the garden.
I think this just means “with all one’s strength” (though I’m not Japanese). Kojien says “加減せずにありったけの力を出してすること” though they don’t always give the full nuance in their definitions
It means just what it sounds like actually. “by relying one ones brute strength” (when there may be an easier way to do it if you were to just think).
力任せに引っ張ったら箪笥（たんす）を壊した。
I broke the dresser when I forcefully pulled it open.
力任せに蹴ったら（けったら）怪我（けが）をした。
I hurt myself when I kicked it with all of my might.