Final answer:
To find the mass of a ball with a downward net force of 20 newtons and an acceleration of 8 m/s², use Newton's second law of motion, resulting in a mass of 2.5 kg.
Step-by-step explanation:
The subject of this question is Physics, specifically related to the area of mechanics involving force, mass, and acceleration, governed by Newton's second law of motion. To determine the mass of the ball when a net force of 20 newtons is applied downward and the ball is accelerating at a rate of 8 m/s², we can rearrange Newton's second law equation, Fnet = ma, to solve for mass (m). Therefore, the mass (m) can be calculated by dividing the net force (Fnet) by the acceleration (a), giving us m = Fnet / a. Using the given values, m = 20 N / 8 m/s², which results in a mass of 2.5 kg.