<span>If it is a single subject, then it needs a single verb (was) but you have to be more specific </span>
Answer:
The answer is: Vibration
Explanation:
Vibration refers to the to and fro motion of a particle or a body. It is used to describe the mechanical oscillation that occurs about the point of equilibrium. This oscillatory motion of the object can be periodic or random.
There are three different types of vibrations: free, forced, and damped vibrations.
