Reggie Bullock added 16 for the Tar Heels (2-0), who shot 44 percent from both the field and the foul line. Still, North Carolina led by double figures throughout the second half before blowing the game open in the final 7 minutes.
McAdoo entered the season expected to take the lead for UNC after the loss of four NBA first-round draft picks. The sophomore had 26 points and 14 rebounds in the season-opening win against Gardner-Webb, then followed that with an 8-for-17 shooting performance against the Owls (0-1).
Greg Gantt scored 18 points to lead Florida Atlantic, which shot 28 percent and had no other player reach double figures.
The game was an opening-round contest in the Maui Invitational, though it is separate from the tournament rounds in Hawaii.
This was North Carolina's last home game until December in a tough opening month of the schedule. The Tar Heels next travel to Long Beach State on Friday night, then head to Hawaii to face Mississippi State to start the Maui Invitational' s tournament rounds. After three games there, North Carolina travels to top-ranked Indiana in the ACC/Big Ten Challenge on Nov. 27.
The Tar Heels don't play at the Smith Center again until facing UAB on Dec. 1.
North Carolina led 32-24 at halftime despite shooting just 34 percent in the opening 20 minutes, then scored five straight points after the break to push the lead to double figures. The Tar Heels maintained a comfortable lead the rest of the afternoon, though they didn't put the Owls away until back-to-back 3-pointers from Bullock and P.J. Hairston that made it 70-48 with about 6 minutes left.
Among the most pressing concerns for UNC coach Roy Williams: the Tar Heels missed a bunch of free throws just as they did in the opener two days earlier. After going just 9-for-19 against Gardner-Webb, the Tar Heels missed 11 of their first 15 free throws and finished at 12-for-27 for the game.
Gantt's 18 points, including four 3-pointers, were the only consistent offense the Owls could muster. The rest of the team shot 23 percent (10-for-44) from the floor, while the bigger Tar Heels took a 56-36 rebounding advantage that led to 16 second-chance points and 10 more shot attempts.