The appropriate downward acceleration for a ball thrown with an initial downward velocity is the acceleration due to gravity, which is 9.8 m/s² on Earth. This is a constant value for all objects in free fall when air resistance is ignored.
The student asked for an appropriate downward acceleration for a ball thrown off a balcony with an initial velocity of 3.0 m/s. The correct acceleration to use is the acceleration due to gravity, which is approximately 9.8 m/s² on Earth. Even though the ball has an initial velocity, gravity will continue to accelerate the ball downwards at this constant rate until it hits the ground, assuming we are ignoring air resistance as stated in the question.
The concept is central to understanding free fall motion, where all objects accelerate downwards at the same rate when resistance forces like air drag are negligible. Therefore, for the ball thrown by Jake, the downward acceleration is indeed 9.8 m/s², regardless of the initial velocity.
In conclusion, in this context, the ball experiences a constant downward acceleration of 9.8 m/s² due to gravity, which is the standard acceleration objects in free fall experience on Earth.