Final answer:
The speed of the 12 kg box after being subjected to a 15 N net force over a 6.0-second interval is 7.5 m/s.
Step-by-step explanation:
To determine the speed of the box at the end of the 6.0-second interval after a 15 N net force is applied, we can use the second law of motion formulated by Isaac Newton, which states that the force acting on an object is equal to the mass of the object multiplied by its acceleration (F = ma).
Since we are given the mass of the box (12 kg) and the net force (15 N), we can calculate the acceleration using the formula a = F/m.
First, we find the acceleration: a = 15 N / 12 kg = 1.25 m/s².
Since the box is initially at rest, it has an initial velocity (u) of 0 m/s. Using the formula for final velocity (v = u + at), we can calculate the speed of the box after 6.0 s:
v = 0 m/s + (1.25 m/s² × 6.0 s) = 7.5 m/s.
Therefore, the speed of the box at the end of the 6.0-second interval is 7.5 m/s.