Question

on a distance vs. time graph, what does a horizontal, flat line indicate about an objects motion?
the object is moving at a constant speed.
the object is accelerating.
the object is at rest (speed is zero).
the object is moving in the opposite direction.

Explanation:

Step1: Analyze the distance - time graph concept

In a distance vs. time graph, the slope of the graph represents the speed of the object. The formula for speed \(v=\frac{\Delta d}{\Delta t}\), where \(\Delta d\) is the change in distance and \(\Delta t\) is the change in time.

Step2: Consider a horizontal, flat line

For a horizontal, flat line on a distance - time graph, \(\Delta d = 0\) (because the distance does not change over time). Using the speed formula \(v=\frac{\Delta d}{\Delta t}\), if \(\Delta d=0\), then \(v = 0\) (assuming \(\Delta t
eq0\)).

Answer:

The object is at rest (speed is zero).