1. the 05.30 flight to malaga takes off with a mass, including fuel, passengers, luggage and crew, of
300,000kg. the gravitational field strength is 10n/kg.
a) the plane climbs to an altitude of 1200m. if the runway was at an altitude of 220m, how much
gravitational potential energy has it gained in kilojoules?
b) by lunchtime, the plane has used up some fuel and is now 50,000kg lighter. how much gravitational
potential energy has the plane lost? (it's still at 1200m.)

which statement about this sum is true? −245+2.7

laticia draws the diagram below to show earth’s magnetic field.

answer

the arrows to the right of earth should point up.

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.