Final answer:
Using kinematics and the quadratic formula, we can infer from provided information that the ball hits the ground at t=2 seconds, and by calculating the trajectory, we can find that the ball will be 6ft above the ground at t=0.54 seconds and t=3.79 seconds.
Step-by-step explanation:
To determine when the ball reaches the ground and how tall the platform is, we need to analyze the motion of the ball using the principles of kinematics. By using the given equations and constants such as the gravitational acceleration (approximately 9.8 m/s²), we can calculate various properties of the ball's trajectory. However, if we're provided with information that at t=2 seconds the ball reaches the ground, we can infer that the initial velocity and the platform's height allowed for 2 seconds of flight before the ball hit the ground.
The question on when the ball will be 6ft above the ground is a matter of finding the time in the ball's trajectory when it passes this height on the way up and on the way down. According to the additional information from the physics equations, it suggests that using the quadratic formula with gravity influencing the ball's motion can yield an answer of t = 0.54 seconds and t = 3.79 seconds, which likely represent the two instances the ball is at 6ft--once while ascending and once while descending.