Distance-Time Graph Motion Analysis

The question asks us to interpret a distance-time graph that is a straight line but is not parallel to the time axis. Let's break down what this means in terms of the object's motion.

Understanding Distance-Time Graphs

A distance-time graph plots the distance traveled by an object against the time elapsed.

• The horizontal axis (x-axis) typically represents time.
• The vertical axis (y-axis) typically represents the distance covered.

Interpreting a Straight Line Graph

When a distance-time graph is a straight line, it means the distance covered is changing at a constant rate over time. The slope of a distance-time graph represents the speed or velocity of the object. A straight line indicates that this slope, and therefore the speed/velocity, is constant.

The Significance of 'Not Parallel to Time Axis'

If the line were parallel to the time axis (horizontal line), it would mean the distance is not changing, indicating the object is stationary (at rest). Since the graph is specified as not parallel to the time axis, it means the distance *is* changing, and therefore the object is in motion.

Conclusion: Constant Velocity

Combining these points:

• A straight line on a distance-time graph means the rate of change of distance (speed/velocity) is constant.
• The line being not parallel to the time axis means the distance is changing, so the object is moving.

Therefore, if the distance-time graph is a straight line but not parallel to the time axis, the object must be moving with a constant velocity.

Why Other Options Are Incorrect

Options involving acceleration imply a changing velocity.

• Non-zero acceleration, constant acceleration, or increasing acceleration would all result in the velocity changing over time. On a distance-time graph, changing velocity is represented by a curved line, not a straight line.

The graph described specifically points to a situation where velocity does not change, hence, constant velocity is the correct conclusion.