Physics Lesson 3.9.1 - Position verse Time Graph in Uniform Motion

Please provide a rating, it takes seconds and helps us to keep this resource free for all to use

Welcome to our Physics lesson on Position verse Time Graph in Uniform Motion, this is the first lesson of our suite of physics lessons covering the topic of Position v's Time and Distance v's Time Graph, you can find links to the other lessons within this tutorial and access additional physics learning resources below this lesson.

Position verse Time Graph in Uniform Motion

As discussed in the tutorial "Speed and Velocity in One Direction", the Position vs Time graph consists in two perpendicular axes where Time is shown in the horizontal axis and Position in the vertical one as shown below:

As you see, the position axis lies both in positive and negative part of coordinate as the position can be also negative but the time axis lies only due positive as no negative time exists.

It is very important to emphasize that the graph does not show the trajectory of the object; it only provides information on how the object moves. That mean if a Position vs Time graph for a uniform motion is like this,

It does not mean the object is ascending an uphill; rather, it only means the object is moving linearly at constant velocity, as at equal time intervals, the position of the object changes uniformly. This conclusion is drawn by considering the concept of "gradient" in Math. It is known that Gradient of a slope is obtained by dividing the change in the vertical coordinate (here the change in position or displacement) to the change in the horizontal one (here the "change in time" or the "time interval involved") as shown below:

From the above reasoning, it is clear that:

• "The gradient of the Position vs Time graph at any point of the graph gives the Instantaneous Velocity".
• If the motion is uniform as in the example shown in the graphs above, the instantaneous velocity is the same everywhere; it is the equal to the average velocity. Therefore, we can write:

Example 1

An object starts moving from x⃗₀ = -12 m and it goes at x⃗₁ = 9m in 7 seconds. After reaching this position it stops for 3 seconds and then moves for other 5 s until it reaches the position x⃗₂ = 4m.

• Plot the position vs time graph for each interval
• Calculate the velocity in each interval

Solution 1

In the first 7 s the object moves from x = -12 m to x = 9 m. Then it stays at x = 9 m for other 3 s (from 7s to 10 s). Finally, it moves from x = 9 m to x = 4m during the last 5s (from 10s to 15s). The position vs time graph is shown below:

The velocity for each interval is

In the second interval there is no motion (x⃗₁ = x⃗₂ = 9m), so the velocity is zero because

In the third interval, we have

You have reach the end of Physics lesson 3.9.1 Position verse Time Graph in Uniform Motion. There are 4 lessons in this physics tutorial covering Position v's Time and Distance v's Time Graph, you can access all the lessons from this tutorial below.

More Position v's Time and Distance v's Time Graph Lessons and Learning Resources

Whats next?

Enjoy the "Position verse Time Graph in Uniform Motion" physics lesson? People who liked the "Position v's Time and Distance v's Time Graph lesson found the following resources useful:

1. Uniform Motion Feedback. Helps other - Leave a rating for this uniform motion (see below)
2. Kinematics Physics tutorial: Position v's Time and Distance v's Time Graph. Read the Position v's Time and Distance v's Time Graph physics tutorial and build your physics knowledge of Kinematics
3. Kinematics Revision Notes: Position v's Time and Distance v's Time Graph. Print the notes so you can revise the key points covered in the physics tutorial for Position v's Time and Distance v's Time Graph
4. Kinematics Practice Questions: Position v's Time and Distance v's Time Graph. Test and improve your knowledge of Position v's Time and Distance v's Time Graph with example questins and answers
5. Check your calculations for Kinematics questions with our excellent Kinematics calculators which contain full equations and calculations clearly displayed line by line. See the Kinematics Calculators by iCalculator™ below.
6. Continuing learning kinematics - read our next physics tutorial: Velocity v's Time and Speed v's Time Graph

Help others Learning Physics just like you

Please provide a rating, it takes seconds and helps us to keep this resource free for all to use

We hope you found this Physics lesson "Position v's Time and Distance v's Time Graph" useful. If you did it would be great if you could spare the time to rate this physics lesson (simply click on the number of stars that match your assessment of this physics learning aide) and/or share on social media, this helps us identify popular tutorials and calculators and expand our free learning resources to support our users around the world have free access to expand their knowledge of physics and other disciplines.

Kinematics Calculators by iCalculator™

• Uniform Motion Calculator
• Uniformerly Accelerated Decelerated Motion Calculator
• Projectile Motion Calculator