Final answer:
To calculate the unbalanced force acting on the 2.5 kg mass that accelerates to 12.0 m/s in 3.0 s, we use Newton's second law and find an acceleration of 4.0 m/s², leading to a force of 10.0 N.
Step-by-step explanation:
The student is asking for the unbalanced force acting on a 2.5 kg mass that, starting from rest, reaches a speed of 12.0 m/s in 3.0 s. To find this force, we can use Newton's second law of motion, which states that force equals mass times acceleration (F = ma). First, calculate the acceleration by using the change in speed over time:
Acceleration (a) = Change in speed / Time taken
a = (12.0 m/s - 0 m/s) / 3.0 s
a = 4.0 m/s2
Now, using the mass (m) of 2.5 kg and the acceleration (a) of 4.0 m/s2:
F = m * a
F = (2.5 kg) * (4.0 m/s2)
F = 10.0 N
The unbalanced force acting on the object is thus 10.0 newtons (N).