Question

choose the best answer from the options that follow each question. the graph below shows the motion of four objects. which of the following lines represent an object in free - fall? assume positive velocity is upward.

Explanation:

Step1: Recall free - fall property

An object in free - fall has a constant acceleration (acceleration due to gravity, $g\approx9.8\ m/s^{2}$ near the Earth's surface). On a velocity - time graph, the acceleration is the slope of the line. For an object in free - fall, the slope of the velocity - time graph is constant.

Step2: Analyze the graph

We need to look for lines on the velocity - time graph that have a constant non - zero slope. A constant slope means a constant acceleration.

Answer:

(No graph details provided to pick a specific option. But the general approach is to look for lines with constant non - zero slope on the velocity - time graph among the given lines I, II, III, IV). If we assume we could analyze the slopes of the lines in the graph properly, we would pick the lines that have a constant non - zero slope as representing an object in free - fall).