A red cross helicopter takes off from headquarters and flies 120 km at 70 degrees south of west. There it drops off some relief supplies, then flies 75 km at 60 degrees west of north to pick up three medics. If the helicoper then heads directly back to headquarters, find the distance and direction it should fly. Give your answers rounded to one decimal place.

130 km at 35.38 degrees north of east

Explanation:

Suppose the HQ is at the origin (x = 0, y = 0)

So the coordinates of the helicopter after the 1st flight is

After the 2nd flight its coordinate would be:

So in order to fly back to its HQ it must fly a distance and direction of

north of east

magnified images possible images can be real = projected onto a screen

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.