Question

Which one of the following moves with a non-uniform velocity?
(A) Light in a homogeneous medium
(B) Sound in a homogeneous medium
(C) A freely falling body
(D) All of the above

Answer 1

Hint
The motions which have accelerated motions is called non-uniform motion. The motion which has constant velocity is called uniform motion. The freely falling body changes its velocity during motion. Speed of both sound and light moves with constant velocity.

Complete step by step answer
Speed of sound and speed of light covers the same distance in same intervals of time in a homogeneous medium. Hence, they move with the constant velocity during their journey. So, they are said to be in uniform motion. Therefore, they both attain uniform velocity.
When the body is falling freely the body accelerates as it moves downwards and therefore, it changes its velocity during its journey. The freely falling body covers unequal distance in equal intervals of time. The speed of a freely falling body varies with the equation- $v = gt$. So, the free falling body attains non-uniform velocity.
Hence, the free-falling body, option (C) is the correct answer.

Note
When a body moves equal distance in equal intervals of time it is said to be uniform motion. This means that this motion covers distance without changing its velocity. When a body covers unequal distance in equal intervals of time it is called non-uniform motion. This happens due to change in velocity during the motion of an object or body. Due to the changing of motion, the non-uniform motions are said to be accelerated motions.