Question

Which of the following graph represents uniform motion (here s is position)

• A. Graph A
• B. Graph B
• C. Graph C
• D. Graph D

Answer 1

Answer: (A)

A

Answer 2

To determine which graph represents uniform motion, we need to understand the definition of uniform motion and how it relates to a position-time (s-t) graph.

Uniform Motion:
Uniform motion is defined as the motion of an object where its velocity is constant. This means both the speed and the direction of motion remain unchanged over time.

Position-Time (s-t) Graph:
On a position-time graph, the slope of the graph represents the velocity of the object. The slope is calculated as: $\text{Slope} = \frac{\Delta s}{\Delta t} = \text{velocity} (v)$

For uniform motion, the velocity (v) must be constant. Therefore, the slope of the position-time graph must be constant. A constant slope is represented by a straight line.

Let's analyze each option:

• Graph A: This graph is a straight line with a positive, non-zero constant slope. This indicates that the position 's' is changing linearly with time 't', and the velocity is constant and positive. This perfectly represents uniform motion.
• Graph B: This graph shows the position 's' remaining at zero for all time 't'. This means the object is at rest at the origin. Its velocity is zero, which is a constant velocity. While technically a form of constant velocity, in the context of "uniform motion" questions, it usually implies non-zero velocity.
• Graph C: This graph consists of two straight line segments with different slopes. The first segment has a positive slope, and the second segment has a negative slope. This means the velocity changes from positive to negative. Therefore, the velocity is not constant, and this does not represent uniform motion.
• Graph D: This graph shows the position 's' remaining at a constant positive value for all time 't'. This means the object is at rest at a fixed position away from the origin. Its velocity is zero, which is a constant velocity. Similar to Graph B, it represents an object at rest.

In typical physics problems, "uniform motion" usually refers to motion with a constant non-zero velocity. Graphs B and D represent an object at rest (zero velocity). Graph C represents motion with changing velocity. Graph A is the standard representation of an object moving with a constant non-zero velocity.