The refractive index of a material is a dimensionless number that describes how fast light travels through the material. It is defined as n={\frac {c}{v}}, where c is the speed of light in vacuum and v is the phase velocity of light in the medium.
the ratio of the velocity of light in a vacuum to its velocity in a specified medium.
<h2>
Number of revolutions required to travel 100 yards is 57.</h2>
Explanation:
Diameter of tire,D = 20 inches
Perimeter of tire = πD
Perimeter of tire = π x 20 = 62.8 inches
Distance traveled = 100 yards
1 yard = 36 inches
Distance traveled = 100 x 36 = 3600 inches
In one revolution it travels 62.8 inches.

Number of revolutions required to travel 100 yards is 57.
Answer:
W = M g = 150 kg * 9.81 m/s^2 = 1470 N
You were only given 3 significant figures in the question.
Answer: Your answer is<u> 1.36.</u>
Hope this helps!