Which of the following is an example of uniform motion?

Uniform motion is when an object is moving in a specific direction at a constant speed.

 A train moving along the tracks at a constant speed is moving in a uniform motion. 

Earth's revolution around the sun is not a uniform motion as the direction of the earth keeps changing while revolving.

Buses that pass through the three markets have a non-uniform circular motion because they cannot keep their speed constant.

A ball falling on a ground is an example of non-uniform motion because the speed of the balls keeps on increasing due to acceleration due to gravity.