This is the 7967th most frequent Japanese word.
大力
Great strength; powerful force.
In this sentence, '大力' is used to denote 'great effort' or 'powerful dedication' in the context of tackling a task or solving an issue.
彼は問題を解決するために大力で取り組んだ。
He dealt with solving the problem with great effort.
Here, '大力' signifies the need for 'great strength or effort' to achieve the goal outlined.
このプロジェクトの成功には大力が必要だ。
This project's success requires great power or effort.
The usage of '大力' in this sentence is to represent 'physical strength or power' in the context of manual labor or moving objects.