Comparing Earth's Orbital & Rotational Periods

AI Thread Summary
The discussion focuses on calculating the ratio of Earth's orbital period around the sun to its rotational period on its axis. Participants emphasize the need for correct values in gravitational calculations, specifically mentioning the gravitational constant and acceleration due to gravity. The conversation also touches on the significance of understanding these periods in relation to defining a year and a day. Users seek clarification on the formulas and values needed for their calculations. The thread highlights the importance of accurate data in solving physics problems related to gravitational forces and motion.
JohnJay
Messages
6
Reaction score
0

Homework Statement



What is the ratio of the Earth's orbital period about the sun to the Earth's period of rotation about its own axis

Homework Equations



none, theory


The Attempt at a Solution



Its theory

Two 335 kg masses (744 lb) are separated by a distance of 5 m. Using Newton's law of gravitation, find the magnitude of the gravitational force exerted by one mass on the other.

F = Gm1m2
______
r (squared)

God... I'm putting it in, but it says its wrong... help...



Joe has a weight of 750 N (about 170 lb) when he is standing on the surface of the earth. What would his weight (the gravitational force due to the earth) be if he tripled his distance from the center of the Earth by flying in a spacecraft ?

The formula should be...

w x a = f

help please!


Thank you members of the community
 
Last edited:
Physics news on Phys.org
The first question should be fairly easy. I assume you've been given the information about both periods of rotation.

For the two masses what answer are you getting? That might help in diagnosing what's going wrong.

Weight is defined as W=mg, where:

g= G\frac{M_E}{r^2}

What will his weight be if r is tripled?
 
What is the ratio of the Earth's orbital period about the sun to the Earth's period of rotation about its own axis
What is the definition of a year timewise? What is significant about the length of a day?

For the second problem, please show the values used, e.g. gravitational constant, G, in the formula.
 
Umm it doesn't say...

and grav. should be 9.81
 
JohnJay said:
Umm it doesn't say...

and grav. should be 9.81

What do you think are the periods for the period of rotation of the Earth and the period of the Earth round the sun. Its fairly obvious.

No, g = 9.81 ms-2 and G = 6.67x10-11 m3kg-1 s-2
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Thread 'Correct statement about a reservoir with an outlet pipe'
The answer to this question is statements (ii) and (iv) are correct. (i) This is FALSE because the speed of water in the tap is greater than speed at the water surface (ii) I don't even understand this statement. What does the "seal" part have to do with water flowing out? Won't the water still flow out through the tap until the tank is empty whether the reservoir is sealed or not? (iii) In my opinion, this statement would be correct. Increasing the gravitational potential energy of the...
Back
Top