A satellite is in a circular orbit about the earth (ME = 5.98 x 10^24 kg). The period of the satellite is 1.26 x 10^4 s. What is the speed at which the satellite travels?

Respuesta :

Answer: [tex]V=5839.051m/s[/tex]  

Explanation:

According to the Third Kepler’s Law of Planetary motion:

[tex]T^{2}=\frac{4\pi^{2}}{GM}a^{3}[/tex]   (1)

Where;:

[tex]T=1.26(10)^{4}s[/tex] is the period of the satellite

[tex]G[/tex] is the Gravitational Constant and its value is [tex]6.674(10)^{-11}\frac{m^{3}}{kgs^{2}}[/tex]

[tex]M=5.98(10)^{24}kg[/tex] is the mass of the Earth

[tex]a[/tex]  is the semimajor axis of the orbit the satllite describes around the Earth (as we know it is a circular orbit, the semimajor axis is equal to the radius of the orbit).

On the other hand, the orbital velocity [tex]V[/tex] is given by:

[tex]V=\sqrt{\frac{GM}{a}}[/tex]   (2)

Now, from (1) we can find [tex]a[/tex], in order to substitute this value in (2):

[tex]a=\sqrt[3]{\frac{T^{2}GM}{4\pi}^{2}}[/tex]   (3)

[tex]a=\sqrt[3]{\frac{(1.26(10)^{4}s)^{2}(6.674(10)^{-11}\frac{m^{3}}{kgs^{2}})(5.98(10)^{24}kg)}{4\pi}^{2}}[/tex]   (4)

[tex]a=11705845.57m[/tex]   (5)

Substituting (5) in (2):

[tex]V=\sqrt{\frac{(6.674(10)^{-11}\frac{m^{3}}{kgs^{2}})(5.98(10)^{24}kg)}{11705845.57m}}[/tex]   (6)

[tex]V=5839.051m/s[/tex]   (7)  This is the speed at which the satellite travels