Define simple harmonic motion and give two examples of the same.

Hint:Simple harmonic motion is quite easy to describe and define as the meaning lies in the name itself, it’s a kind of motion which is the simplest of all the harmonic motions or oscillatory motions possible.

Complete step by step answer:
As we explained in the hint section of the solution to the question, Simple harmonic is a kind of motion which is the simplest of all the possible harmonic and oscillatory motions, whose study is the most basic and the easiest. To define simple harmonic motion, we first need to discuss a little bit about periodic and aperiodic motions.
In very simple words, periodic motion is the motion that repeats itself in equal intervals or periods of time. On the other hand, any motion that has no certain cycle and doesn’t repeat itself after a specific period of time is called aperiodic motion, as the name suggests.

Now that we know about periodic motion, we can easily define simple harmonic motions as:

Simple harmonic motion is a type of periodic or oscillatory motion in which certain conditions are set to be met, like, in a simple harmonic motion, the amplitude is constant. In any simple harmonic motion, acceleration acting on the body is always proportional and oppositely directed to the displacement of the body from its mean position. Mean position of a body in simple harmonic motion or SHM is a position of equilibrium, i.e. all the forces cancel out each other and the net force acting on the body at this position is equal to zero.

Examples of simple harmonic motion:
-The projection on any diameter of a point in uniform motion around a circle. In simpler words, one-dimensional projection of uniform circular motion along any of the two coordinates of the plane.
-A simple pendulum is the most popular, most basic and most frequently used example of simple harmonic motion.

Note:It is a point to be noted that although all Simple harmonic motions are periodic and oscillatory, not all periodic or oscillatory motions are simple harmonic motion. There are certain conditions that need to be met for any oscillatory or periodic motion to be considered as a simple harmonic motion. These conditions are mentioned above in the answer.