Bianca is standing at x =600m. firecracker 1, at the origin, and firecracker 2, at x =900m, explode simultaneously. the flash from firecracker 1 reaches bianca's eye at 4.0 μs . part a at what time does she see the flash from firecracker 2?

Explanation:

Given

Bianca is at

i.e. distance between origin and Bianca is

time taken to reach Bianca eyes is

i.e. Cracker exploded at because it is observed at

Time taken by second cracker flash to reach Bianca eyes

Therefore it will be observed at

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.