There are several different possibilities.
==> If the 5.0 means 5 miles per hour, that's 2.24 meters per second, up.
The acceleration of gravity is 9.8 m/s down, so the ball stops, turns around, and starts falling in (2.24/9.8) = 0.229 second. Then, after is starts to fall, it takes the same amount of time to the person's hand.
Total time = 0.457 second.
==> If the 5.0 means 5 meters per second, up . . .
The acceleration of gravity is 9.8 m/s down, so the ball stops, turns around, and starts falling in (5.0/9.8) = 0.51 second. Then, after is starts to fall, it takes the same amount of time to the person's hand.
Total time = 1.02 second.
==> If the 5.0 means 5 km/minute, that's about 83.33 meters per second, up.
The acceleration of gravity is 9.8 m/s down, so the ball stops, turns around, and starts falling in (83.33/9.8) = 8.503 seconds. Then, after is starts to fall, it takes the same amount of time to the person's hand.
Total time = 17.01 seconds.
==> If the 5.0 means 5 furlongs per fortnight, that's about 0.00083 meters per second, up.
The acceleration of gravity is 9.8 m/s down, so the ball stops, turns around, and starts falling in (0.00083/9.8) = 0.000085 second. Then, after is starts to fall, it takes the same amount of time to the person's hand.
Total time = 0.00017 second.
This is why all of your numbers always need their units.