contestada

A satellite of mass ms travels in a circular orbit of radius a around a planet of mass mp?ms.

Part A

Derive expressions for the orbital speed of a satellite.

Express your answer in terms of some or all of the variables mp, ms, a, and gravitational constant G.

vs =

Respuesta :

Answer:

Orbital speed of the satellite is  [tex]\frac{\sqrt{Gm_p} }{a}[/tex] .

Explanation:

Given:

Gravitational constant = [tex]G[/tex]

Mass of the satellite = [tex]m_s[/tex]

Mass of the planet = [tex]m_p[/tex]

Radius of the orbit = [tex]a[/tex]

We have to derive the expressions for the orbital speed.

Let the orbital speed be 'vs'.

According to the question:

Force between the planet and the satellite.

From universal law of gravitation.

⇒ [tex]F=\frac{Gm_pm_s}{a^2}[/tex] ...equation (i)

And

Their is centripetal force acting towards the planet.

And we know centripetal acceleration [tex]a_c[/tex] = [tex]\frac{v^2}{r}[/tex] .

From Newtons second law.

⇒ [tex]F=ma[/tex]

⇒ [tex]F=m\frac{v^2}{r}[/tex]

Here the velocity is vs and r = a and mass of the satellite is ms.

⇒ [tex]F=m_s\frac{v_s^2}{a}[/tex]    ...equation (ii)

Equating both the equations.

equation (i) = equation (ii)

⇒ [tex]\frac{Gm_pm_s}{a^2} = m_s\frac{v_s^2}{a}[/tex]

⇒ [tex]\frac{Gm_p}{a} =v_s^2[/tex]

⇒ [tex]\sqrt{\frac{Gm_p}{a} } =v_s[/tex]

So,

The orbital speed of the satellite is Sq-rt(Gm_p/a).