How to use "pop" in a sentence

For several seconds she was certain that she could feel the switch straining under her fingertip as it tried to pop on.

"Oh, I'll probably pop in and out a few times."

"You don't want to pop in here?"

A five-piece band hammered out wildly amplified pop music from the small stage in the open cocktail lounge beyond and slightly above the slot machines

"Well, he still might pop up here