Question

A 400 kg satellite is in a circular orbit at an altitude of 550 km above the Earth's surface. Because of air friction, the satellite eventually falls to the Earth's surface, where it hits the ground with a speed of 1.90 km/s. How much energy was transformed into internal energy by means of air friction?
J

Answer 1

here,

mass of satellite , m = 400 kg

mass of earth , M = 5.98 * 10^24 kg

final speed when it hits the ground , v = 1900 m/s

the energy transformed into internal energy by means of air friction , E = change in total energy

E = (0.5 * m * v^2 + G * M * m /( r )^2) - G * M * m /( r + A)^2

E = ( 0.5 * 400 * 1900^2 + 6.67 * 10^-11 * 5.98 * 10^24 * 400 /( 6.371 * 10^6 )^2 ) - 6.67 * 10^-11 * 5.98 * 10^24 * 400 /( 6.371 * 10^6 + 5.5 * 10^5)^2 J

E = 7.2 * 10^8 J

the energy transformed into internal energy by means of air friction is 7.2 * 10^8 J