Question

The motion of the second's hand in a clock is an example of:
A) Uniform motion
B) Non-uniform motion
C) A combination of uniform and non-uniform motion
D) Neither uniform nor non-uniform motion

Answer 1

In a uniform circular motion, the object moves with uniform speed along the circumference of a circle. But the velocities are different at different points due to the change in the direction of velocity. If an object is moving with uniform speed if it covers equal distances in equal intervals of time, however small the intervals are.

Complete step by step solution:
If it is in uniform motion, the object traveling in a straight line will have the same average and instantaneous velocities. In a uniform circular motion, the object will be traveling along the circumference of a circle, covering equal distance at equal intervals of time. In uniform motion, the speed of the object will be steady and the acceleration will be zero. The graph between distance and time will be a straight line
The motion of a second hand in a clock has a constant speed and it covers equal distance at an equal interval of time but changes the direction. Hence the second's hand of the clock is an example of non-uniform motion.

The answer is Option (B): Uniform motion.

Note: The motion in which the body moves with variable speed and non-zero acceleration is called non-uniform motion. The body will not cover an equal distance in an equal interval of time. The speed of the object will be different from the actual speed. The instantaneous speed will be different at different instants. The graph between distance and time will be a curved line. In a non-uniform circular motion, the object travels with variable angular speed around a fixed point. It will have a radial acceleration due to the change in velocity at each instant.