I\'m really confused on these astronomy hw questions. Can someone please show me
ID: 157667 • Letter: I
Question
I'm really confused on these astronomy hw questions. Can someone please show me the actual calculations, not just answers? Thanks!
3. The synodic period of Mars is 2.14 years, what is its sidereal period? The synodic period of Mercury is 0.32, what is its sidereal period?
Heliocentric: And S is 2.14 for Mars and 0.32 for Mercury and Solve for P and P(Earth) is always 1 year. The answer should be between 1 and 2 years for Mars and 0.1 and 0.3 for Mercury.
4. If a planet has a period of 6.5 years what is its distance from the Sun? If it has a semi-major orbit of 8.5 A.U., what is its sidereal period?
Heliocentric: Use P^2 = a^3 for both parts. Just realize you are solving for a in the first and P in the second. The answer for the first part is between 2 and 5 A.U. The answer for the second is between 23 and 26 years.
5. If Jupiter moved to twice the distance from Earth would the planet exert ½ or ¼ the force it does now on the Earth?
Galileo and Newton: F=GMm/R^2 and just double the R and see what happens.
6. An apple fell for 60 seconds onto Newton’s head. How tall is the tree from which the apple fell?
In-class Galileo and Newton: d=(1/2)gt^2 where g = 9.8 m/s^2. The answer is between 14,000 and 18,000 km.
7. What is the force between Jupiter and the Sun? Between Saturn and the Sun? How many times is the force between Jupiter/Sun versus Saturn/Sun? (Hint: Fjs/Fss)
Galileo and Newton (Force of the Sun on Venus): Use F=Mm/R^2 and use the values for M= mass of the sun m= mass of Jupiter or Saturn and R = semimajor axis in m where 1X10^3 m (1000 m) = 1 km. The answers for this are around 4X10^23 N for the Sun and Jupiter and 3X10^22 N for the Sun and Saturn. And the ratio is around 11.
8. What is the frequency of light that is 6.365X10-10m? (Remember that the speed of light is 3.000X108 m/s)
Light and Telescopes: f=c/wavelength and c=3X10^8 m/s. The answer is around 4X10^17 Hz.
9. What is the energy of the particle of light with a wavelength of 6.365X10-10m? (Remember Planck’s Constant, h, is 6.63X10-34Js)
Light and Telescopes: E=hf and use the f that you received from the above problem. The answer is around 3X10^-16 J.
10. What is the light gathering power between a 1000 meter telescope versus a 10 meter telescope?
Light and Telescopes: LGP = (D1/D2)^2. The answer is between 100 and 100,000 X.
Explanation / Answer
Formula to solve these questions are:-
3:- for planet towards the sun from earth formula is 1/P= 1/E+1/S
for planet after earth in solar system 1/P= 1/E-1/S
E=1 , p is the synodic period and s is the sideral period
4 )cube of the semi-major axis is equal to the orbital period squared times the total mass of the orbiting bodies.
(8.5)^3=P^2*1
24.77 is the period of the planet
now use the above question 3 formula to calculate the sidereal period , take E=6.5 year
5) it is inversely proportional to square of distanc ebetween them, 1/4 times is the right answer
6) formula is t= srare root( 2h/g)
put values and get the answer
7) F= (Gm1mi2)/r^2 .
jut put the values and take rtio . we can solve this by just comparing the distances between them
8) velocity = frequency * wavelength
3*10^8=frequency*6.36*10^-10
is the answer
9) yes the formula is correct . just apply it and answer will be right
10)100^2 =10000 is the right answer