The discussion revolves around calculating the time for one revolution of a cylinder with a radius of 0.90 km, given that the gravitational acceleration at its surface is 9.8 m/s². The problem involves concepts from rotational dynamics and angular motion.
Participants are actively engaging with the problem, with some providing calculations and others questioning the steps taken. There is a recognition of errors in previous calculations, and a few participants are exploring the implications of their findings without reaching a consensus on the final answer.
There are mentions of confusion regarding the use of radius versus diameter, and some participants express uncertainty about the values needed to proceed with calculations. The discussion reflects a collaborative effort to clarify the problem's requirements and assumptions.
Which other variable do you think you have no value for?ross moldvoer said:Homework Statement
For a 0.90km radius cylinder, find the time for one revolution if "gravity" at the surface is to be 9.8 m/s2.
Homework Equations
rω^2=a
The Attempt at a Solution
i tried solving for omega but i couldn't find a solution that i only had 1 variable in it.
i don't know the velocity for solving for omega, is this what you meant?haruspex said:Which other variable do you think you have no value for?
I don't know where you are stuck. The first step is to calculate ω - can you do that from the formula you quoted? Next, as gneill says, you can find the time of one revolution from ω. Is that part your problem?ross moldvoer said:i don't know the velocity for solving for omega, is this what you meant?
In the OP you quoted the right equation to be using. That has three variables and you are given the values of two of them. Forget v for now.ross moldvoer said:i know that ω = v/r but i do not know v. I guess i am confused about what to do in order to solve for ω.
Ok, but why did you halve it to 450? Either way, I don't get .133.ross moldvoer said:wow can't believe i missed that. so then 450ω^2=9.8, ω=.133
i converted .9 km to 900 m
the cylinder's diameter is 900m and i need the radius. 900/2=450. then i did 9.8/450=ω^2=.022, ω=.147haruspex said:Ok, but why did you halve it to 450? Either way, I don't get .133.
It says radius.ross moldvoer said:the cylinder's diameter is 900m
my badharuspex said:It says radius.
Sounds right.ross moldvoer said:my bad
then i get .104
You know what I'm going to say, surely? Please post your working and answer.ross moldvoer said:so after this do i just plug it into the equation? the answer i get seems high