The perihelion (Rp) of Mars’ orbit is 1.381 AU while its aphelion (Ra) is 1.666 AU. Using the relation Rp = a(1 - e) and Ra = a(1 + e),where a is the length of the semi-major axis and e is the eccentricity of the orbit, calculate a and e for Mars’ orbit around the Sun. Show all of your work

Respuesta :

ANSWER:

a = 1.523

e = 0.09353

STEP-BY-STEP EXPLANATION:

From the statement we can establish the following two equations:

[tex]\begin{gathered} R_p=a\mleft(1-e\mright)\rightarrow a=\frac{R_p}{1-e}\text{ (1)} \\ R_1=a\mleft(1+e\mright)\rightarrow a=\frac{R_a}{1+e}\text{ (2)} \end{gathered}[/tex]

We equate both equations and solve for e, like this:

[tex]\begin{gathered} \frac{R_p_{}}{1-e}=\frac{R_a}{1+e} \\ \frac{1.381}{1-e}=\frac{1.666}{1+e} \\ (1.381)\cdot(1+e)=(1.666)\cdot(1-e) \\ 1.381+1.381e=1.666-1.666e \\ 1.666e+1.381e=1.666-1.381 \\ 3.047e=0.285 \\ e=\frac{0.285}{3.047} \\ e=0.09353 \\ \\ \text{now, for a, replacing in (1):} \\ a=\frac{1.381}{1-0.09353} \\ a=1.523 \end{gathered}[/tex]