Final answer:
To find the time it takes for an object to reach maximum height, we can use the time of ascent formula. With an initial velocity of 12 m/s and acceleration due to gravity of 1.5 m/s², the object takes 8 seconds to reach maximum height, which corresponds to option A.
Step-by-step explanation:
To determine how long it takes for an object to reach its maximum height, we can use the formula for the time of ascent under uniform acceleration, which is derived from the kinematic equations of motion. The formula is: time = (final velocity - initial velocity) / acceleration. Since the final velocity at the maximum height is 0 m/s (the object momentarily stops before descending), we can rearrange the formula to solve for time:
time = (0 m/s - initial velocity) / (acceleration due to gravity)
Given the initial velocity of 12 m/s and the acceleration due to gravity of 1.5 m/s² on planet X, we can plug these values into the equation:
time = (0 m/s - 12 m/s) / (-1.5 m/s²) = 8 seconds
Therefore, the correct answer is A. 8.0 s, which is the time it takes for the object to reach the maximum height on planet X.