know what's going on vs be on the ball

know what's going on and be on the ball both are verbs.

Word	Noun	Adjective	Verb	Adverb
know what's going on	No	No	Yes	No
be on the ball	No	No	Yes	No

As verbs, know what's going on and be on the ball are synonyms defined as:

Other synonyms of know what's going on include be with it, know the score, know what's what.

know what's going on (verb)	be on the ball (verb)
be well-informed	be well-informed