To determine which object is maintaining a constant speed according to Newton's law of inertia, we need to analyze the net forces acting on each object.
Newton's first law states that an object at rest stays at rest, and an object in motion continues to move at a constant speed in a straight line unless acted upon by a net external force.
Let's calculate the net forces for each object:
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Object 1:
- Left: 5 N (left)
- Right: 5 N + 5 N = 10 N (right)
- Net force = \(10 N - 5 N = 5 N\) (right)
- Not constant speed (there is a net force).
-
Object 2:
- Left: 1 N + 12 N = 13 N (left)
- Right: 2 N + 6 N = 8 N (right)
- Net force = \(8 N - 13 N = -5 N\) (left)
- Not constant speed (there is a net force).
-
Object 3:
- Left: 5 N (left)
- Right: 8 N (right)
- Net force = \(8 N - 5 N = 3 N\) (right)
- Not constant speed (there is a net force).
-
Object 4:
- Left: 4 N + 2 N = 6 N (left)
- Right: 6 N (right)
- Net force = \(6 N - 6 N = 0 N\)
- It is maintaining constant speed (no net force).
Therefore, Object 4 is maintaining a constant speed, as there is no net force acting on it.