Virus. it's only living when it enters a host's body as it's a parasitic organism
He proposed the theory of Continental Drift. He believed that all of the continents were once joined together in a super continent he called Pangea (not sure if that's spelled right I studied this awhile ago). He proved this by showing similarities in fossils in completely different continents and showing how well the continents could fit together.
Answer:
= 2.33
Explanation:
.According to snell's law:
n1sin i = n2sin r ,
where n1 is refractive index of the medium in which incident ray is travelling, n2 is the refractive index of the medium in which refracted ray is travelling,
i is angle of incidence,
r is angle of refraction.
Given that,
n1 = 1,
i = 51 degrees,
r = 19.5 degrees. ,
n2= ?
So,
1*sin 51 = n2 sin 19.5
=> n2 = sin51 / sin19.5
= 2.33