Answer:
Gravity as well as electrostatic and magnetic attraction and repulsion provide real life examples of forces being exerted by one object on another without them being in contact with each other. Many children are aware of magnetism and have played with fridge magnets.
The required value of the index of refraction of glass is 1.5.
Given data:
The speed of light in a vacuum is,
.
The speed of light in a glass is,
.
Light has the tendency to travel from one medium to another, then the difference between the speeds of light in various mediums is determined by a term, known as the index of refraction. The mathematical expression for the index of refraction of glass is,
n = c / v
Solving as

Thus, we can conclude that the required value of the index of refraction of glass is 1.5.
Learn more about the index of refraction here:
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