raise
扛 centers on lifting or raising something, often with effort or using the hands.
扛 combines 扌 (hand) with 工, which likely contributes the sound and may suggest the idea of working or effort. The character expresses lifting or raising by hand.
The hand radical 扌 beside 工 (work) suggests using your hands to lift something heavy, like a worker raising a load.
For コウ, imagine a construction worker using a crane to raise a steel beam, and the crane makes a low 'koh' sound as it lifts: koh -> コウ.