The Helios B spacecraft had a speed of 71 km/s when it was
4.3km from the sun.
Prove that its orbit about the sun was closed
andtherefore eliptical.

Respuesta :

Explanation:

It is given that,

Speed of the spacecraft, v = 71 km/s = 71000 m/s

Distance between the spacecraft and the Sun, [tex]d = 4.3\times 10^7\ km = 4.3\times 10^{10}\ m[/tex]

It is required to proof that its orbit about the sun was closed  and therefore elliptical. Let v is the speed with which the spacecraft if it is moving in circular path. It is given by :

[tex]v=\sqrt{\dfrac{GM}{r}}[/tex]

M is the mass of the sun, [tex]M=2\times 10^{30}\ kg[/tex]

[tex]v=\sqrt{\dfrac{6.67\times 10^{-11}\times 2\times 10^{30}}{4.3\times 10^{10}}}[/tex]    

v = 55698 m/s

or

v = 55.6 km/s

The given velocity is 71 km/s while the calculated value of velocity is 55.6 km/s. It is clear that the path is not circular. It is elliptical. Hence, this is the required solution.