5. now lets make period measurements for different orbits of the solar system. then, calculate the relation…

5. now lets make period measurements for different orbits of the solar system. then, calculate the relation of t/a. for this, remember to use the target orbit panel to recreate real world orbits! target orbit: mars period, t (years) semi - major axis, a (au) t/a (au/years) mercury earth mars 6. do you see any patterns of period vs semi - major axis? a. does the relation t/a change? how much? b. for which planets is it bigger? c. draw the shape of the graph: 7. find the combination of exponents for which the relation t/a remains constant (1.0) for all orbits. include a drawing of the graph, what shape does the graph have now? period power: t semi - major axis power: a graph:
Answer
Explanation:
Step1: Recall orbital - period and semi - major axis data
For Mercury: The period $T_{Mercury}\approx0.241$ years and semi - major axis $a_{Mercury}\approx0.387$ AU. Then $\frac{T_{Mercury}}{a_{Mercury}}=\frac{0.241}{0.387}\approx0.623$ AU/years.
Step2: Calculate for Earth
For Earth: $T_{Earth} = 1$ year and $a_{Earth}=1$ AU. Then $\frac{T_{Earth}}{a_{Earth}}=\frac{1}{1}=1$ AU/years.
Step3: Calculate for Mars
For Mars: $T_{Mars}\approx1.88$ years and $a_{Mars}\approx1.524$ AU. Then $\frac{T_{Mars}}{a_{Mars}}=\frac{1.88}{1.524}\approx1.234$ AU/years.
Step4: Analyze patterns
a. The relation $\frac{T}{a}$ changes. The differences are: $\Delta_{1}=1 - 0.623 = 0.377$ (between Earth and Mercury) and $\Delta_{2}=1.234 - 1=0.234$ (between Mars and Earth). b. $\frac{T}{a}$ is bigger for Mars compared to Earth and Mercury. c. The graph of $T$ vs $a$ is a curve. As $a$ increases, $T$ increases, but not linearly.
Step5: Find constant - relation exponents
Kepler's third law states that $T^{2}=k\cdot a^{3}$ (where $k$ is a constant). If we rewrite it in terms of a constant $\frac{T^{n}}{a^{m}} = 1$, we find that when $n = 2$ and $m = 3$, $\frac{T^{2}}{a^{3}}$ is constant for all orbits in the solar - system. The graph of $T^{2}$ vs $a^{3}$ is a straight line passing through the origin.
Answer:
| Planet | Period, T (years) | Semi - major axis, a (AU) | T/a (AU/years) |
|---|---|---|---|
| Mercury | 0.241 | 0.387 | 0.623 |
| Earth | 1 | 1 | 1 |
| Mars | 1.88 | 1.524 | 1.234 |
| a. The relation $\frac{T}{a}$ changes. Differences are 0.377 (Earth - Mercury) and 0.234 (Mars - Earth). | |||
| b. It is bigger for Mars. | |||
| c. The graph of $T$ vs $a$ is a curve. | |||
| For the constant relation, period power $n = 2$, semi - major axis power $m = 3$, and the graph of $T^{2}$ vs $a^{3}$ is a straight line. |