A 500 kg satellite is placed in a circular orbit 7500 km above the surface of the earth. At this elevation, the acceleration of gravity is 4.09 m/s2. Knowing that its orbital speed is 20,000 km/h, determine the kinetic energy of the satellite

7.7 GJ

Explanation:

Kinetic wnergy is given by

KE=½mv²

Where KE denote kinetic energy, m is the mass of object and v is velocity. Normally, m is in Kg and v in m/s

Conversion

Given speed of satelite in km/h, we convert it into m/s by multiply by 1000/3600

20000*1000/3600=5555.5555555555

Rounded off, m=5555.56 m/s

Substituting 500 kg for m and 5555.56 m/s for v then

KE=½*500*5555.56²=7,716,061,728.4 rounded off as

KE=7.7 GJ

d is the correct answer