Final answer:
Without specific information on the motion of the object beyond 11 seconds, we cannot accurately determine the instantaneous velocity of the object at 20 seconds after it is released from rest.
Step-by-step explanation:
The instantaneous velocity of an object released from rest 20 seconds after it is released can be derived from the description of its motion. Given that the object's velocity is increasing with time according to the equation v(t) = 3.2t m/s, and, at 5 seconds, it begins decelerating according to the equation [16.0 - 1.5(t–5.0)] m/s, we can understand that for the first 5 seconds velocity increases, and then it starts to decrease.
However, we do not have a specific function of the velocity after 20 seconds, additional information is required to determine the exact instantaneous velocity at that moment. Without that information, we cannot conclude whether the velocity is constant, increasing, or decreasing at the 20-second mark, so answering this specific question accurately is not possible. We need further details about the motion of the object from 11.0 seconds onwards to determine the instantaneous velocity at 20 seconds.