Answer:Joe's velocity leaving the ground is 1.00 m/s.
Explanation: The velocity of Joe immediately after leaving the ground can be calculated using the formula v = at, where a is the acceleration and t is the time. Joe's acceleration can be found using the equation F = ma, where F is the net force and m is the mass.So, Joe's acceleration can be calculated as a = F/m = 100N / 90kg = 1.11 m/s^2.Then, using v = at, we can calculate Joe's velocity as v = 1.11 m/s^2 x 0.9 s = 1.00 m/s. Therefore, Joe's velocity immediately after leaving the ground is 1.00 m/s.