Question

Which of the following is/are the example(s) of one dimensional motion?
(A) Motion of a vehicle in straight line
(B) Motion of a train on a straight railway track
(C) Motion of an object dropped from a certain height from the ground
(D) A man working on a straight path

Answer 1

Hint In order to classify these as one dimensional motion or not, let us first understand what one dimensional motion actually is. Generally , one dimension motion is referred to as objects that are moving in straight lines. Considering this definition, let’s answer the following.

Complete Step By Step Solution
A body or a particle is said to be in a one dimensional motion if it is moving in a single direction during its course of journey. Its motion can be described using displacement from the starting point to end point, time , velocity and its acceleration throughout its journey.
Now in our first example, it is given that the motion of a vehicle is said to be in a straight line. It doesn’t move or deviate from it’s path or neither does it go in a circular path. Thus, it is a proven example of a one dimension motion.
Train moving on a straight railway track without any deviations or change in motion with respect to the reference frame is an example of a one dimensional motion. Now the third example given is a ball dropped from a certain height from the ground. This motion is only possible due to gravitational force and it is not varying with respect to position since earth’s gravity is said to be constant. Hence, this is also said to be a one dimensional motion.
A man working on a straight path is also an example of one dimensional motion as the work done by the man is unidirectional and straight. Hence , all the four options are examples of one dimension motion.

Note Motion occurring with respect to a position or a plane is called two dimensional motion and motion that incorporates all the axes are called three dimensional motion. Gyroscope is a perfect example of a three dimensional motion.