expression, ichidan verb
set off an explosive; blast
Literal meaning: to detonate an explosive charge, especially in mining or construction. This is the original, technical sense.
工事現場でハッパをかける作業は、資格を持った人だけが行える。
Only qualified personnel can carry out blasting work at the construction site.
expression, ichidan verb
give a pep talk; fire up; motivate with strong words
Figurative use: to strongly encourage or push someone, often with rough or forceful language. Common in workplace or sports contexts.
監督が選手たちにハッパをかけて、後半の試合に臨んだ。
The coach fired up the players before they faced the second half of the match.
上司にハッパをかけられて、やる気が出た。
My boss gave me a pep talk and I felt motivated.