Determining Orbital Period of a Planet

AI Thread Summary
The discussion focuses on calculating the orbital period of Earth using the formula P² = (4 * π² * a³) / (G(M+m)). The user initially obtained a value of P = 31690989.27 but was confused about the units, mistakenly arriving at s kg⁻². Another participant clarified that P represents time in seconds and suggested converting seconds to years for comparison. The user acknowledged the oversight and thanked the participant for the help, highlighting the importance of unit conversion in calculations.
polskamafia
Messages
2
Reaction score
0
Using the equation P2 = (4 * pi2 * a3)/(G(M+m)) to find the orbital period of Earth where:

P = orbital period
a = semi-major axis = 1.50e11 m
G = 6.67e-11 m3 kg-1 s-2
M = mass of sun (in this case) = 1.989e30 kg
m = mass of Earth = 5.972e24 kg

I have been trying to find the orbital period of the Earth but the answers I've been getting make no sense.

P2 = (4 * pi2 * (1.50e11)3) / (G(1.989e30 + 5.972e24))

P = 31690989.27

What are the units on P? I tried following the units as they canceled each other and I ended up with s kg-2. Any advice would be helpful.

Thanks!

- Marcin
 
Physics news on Phys.org
P has units of seconds.
 
Hello Marcin

Try calculating how many seconds there are in a year. And compare with your answer.
 
Ah yes. Well that was embarrassing. Thank you Bandersnatch!
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'Collision of a bullet on a rod-string system: query'

Thread 'Collision of a bullet on a rod-string system: query'

In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Calculating Angle & Speed to Reach Planet's Moon from Station Orbit
Replies
1
Views
2K
B Use Surface-Volume to approximate gravity for planets and protons
Replies
6
Views
421
What is the orbital period of an asteroid between Earth and Jupiter?
Replies
2
Views
2K
Calculating Solar Mass using peak Doppler shifts
Replies
7
Views
2K
From circular orbit to elliptical orbit
Replies
3
Views
2K
How much work is done when a satellite is launched into orbit?
Replies
5
Views
2K
What is the period of this binary orbit?
Replies
3
Views
1K
Period of Planets orbiting a Star
Replies
13
Views
8K
Finding the astronaut's weight on a planet's surface
Replies
9
Views
3K
Finding Orbital Period of Unknown Planet
Replies
5
Views
2K

Hot Threads

Recent Insights

Back
Top