Larger than one.
In fact, the index of refraction of a medium is the ratio between the speed of light in vacuum (c) and the speed of light in that medium (v):
But the maximum speed the light can travel at is exactly c, the speed of light in vacuum: so v is always less (or equal, in case of vacuum) than c, and so n is always greater than 1.
It’s D. The pitch would be lower. I’m 100% sure. I just took the test. I hope this helps you!! <3
Lamina occupies x² + y² = 14y. Outside circle is x² + y² = 49
To find the mass of lamina, integrate given density function over the region
m = ∫∫D P(x, y) dA
Subtitute x = r cosФ and y = r sinФ in x² + y² = 14y
and x² + y² = 49
x² + y² = 14y
(r cosФ)² + ( rsinФ)² = 14(rsinФ)
r² = 14r sin Ф
x² +y² = 49
r² = 49
r = 7
Cntre mass (-x. -y)
-x= i/m ∫∫D xp(x,y) dA = 1/m∫∫ (r cosФ) p( r, Ф)r
dr dФ
-y = 1/m∫∫D yp(x, y) dA = 1/m ∫∫D (r sinФ) p(r, Ф) r drФ
where m = ∫∫D p(x, y) dA