Distance-Time Graph

Introduction

A distance-time graph shows how the distance travelled by an object changes with time. In this graph, time is taken on the X-axis and distance is taken on the Y-axis. It helps us understand whether an object is moving with constant speed, changing speed, or is at rest.

What Does a Distance-Time Graph Show?

A distance-time graph gives a clear picture of motion. If the graph rises steadily, the object is moving with uniform speed. If the graph is horizontal, the object is at rest. If the graph is curved, the object is moving with non-uniform speed.

---

Uniform Motion

In uniform motion, the object covers equal distances in equal intervals of time. Therefore, the distance-time graph is a straight line with constant slope.

Example: A car moves 10 m every second.

Illustration of Uniform Motion:

---

Object at Rest

When an object is at rest, its distance does not change with time. Therefore, the distance-time graph is a horizontal straight line.

Example: A bag remains at the same place for 10 s.

Illustration of Object at Rest:

---

Non-Uniform Motion with Increasing Speed

When an object covers more distance in equal intervals of time, its speed increases. In this case, the distance-time graph is a curve that becomes steeper with time.

Example: A bicycle starts slowly and then moves faster.

Illustration of Increasing Speed:

---

Non-Uniform Motion with Decreasing Speed

When an object covers less distance in equal intervals of time, its speed decreases. In this case, the distance-time graph is a curve that becomes less steep with time.

Example: A moving ball slows down gradually.

Illustration of Decreasing Speed:

---

Important Points

• A straight sloping line shows uniform motion.
• A horizontal line shows that the object is at rest.
• A curve getting steeper shows increasing speed.
• A curve becoming flatter shows decreasing speed.
• The slope of a distance-time graph represents speed.

Conclusion

A distance-time graph is a simple and useful way to understand motion. By looking at its shape, we can know whether an object is moving uniformly, changing its speed, or not moving at all.