Final answer:
The acceleration of the mass after falling for 6.0 seconds on Planet X will be 4.0 m/s², which is the gravitational acceleration of Planet X calculated from the given weight of the mass.
Step-by-step explanation:
To determine the acceleration of a 15-kg mass after falling for 6.0 seconds on Planet X, we start by using the given weight of the mass, which is 60.0 N. The weight (w) of the mass is related to the gravitational acceleration (g) on Planet X and the mass (m) by the equation w = mg. Hence, we can calculate g as follows:
w = mg
60.0 N = (15 kg)(g)
g = 60.0 N / 15 kg = 4.0 m/s²
The gravitational acceleration (g) is 4.0 m/s² on Planet X. When the mass is released and falls freely, it accelerates at this constant rate due to gravity, irrespective of the time it has been falling. Therefore, the mass will accelerate at 4.0 m/s² after 1 second or even after 6.0 seconds, as long as it is in free fall and air resistance is negligible.