The Original Gay Porn Community - Free Gay Movies and Photos, Gay Porn Site Reviews and Adult Gay Forums

  • Welcome To Just Us Boys - The World's Largest Gay Message Board Community

    In order to comply with recent US Supreme Court rulings regarding adult content, we will be making changes in the future to require that you log into your account to view adult content on the site.
    If you do not have an account, please register.
    REGISTER HERE - 100% FREE / We Will Never Sell Your Info

    PLEASE READ: To register, turn off your VPN (iPhone users- disable iCloud); you can re-enable the VPN after registration. You must maintain an active email address on your account: disposable email addresses cannot be used to register.

Is anyone here good at physics? I need a solution to a mechanics problem

bruce379

Sex God
Joined
Jun 18, 2013
Posts
541
Reaction score
4
Points
0
Location
brooklyn
(Imagine a setup almost like a cassette tape arrangement). The description below is sufficient to draw a diagram of the mechanical arrangement and vectors.

Consider 2 spindles s1 and s2 that can rotate on their axes.
Their centers are located along the x-axis:
s1 at the origin (0,0) and
s2 at a distance d, (d, 0).

Call the constant spindle radius of s1, r1.
Call the constant spindle radius of s2, r2.
An unknown length of tape, L, and constant thickness, e, is tightly wound on s1.
The radius of the WOUND spindle s1 with the tape is R1, measured from the origin.
The end of this tape is attached to s2. R1>=r1.
The radius of the WINDING spindle s2 with the tape is R2, measured from the axis of s2. R2>=r2

The tape leaves s1 at point A, and winds into s2 at point B. Both A and B are located on the 1st quadrant. Assume negligible sagging of the tape from A to B. Therefore the tape leaves A tangent to R1 and enters B tangent to R2.

Let s2 be the driver spindle rotating at constant clockwise angular velocity omega2.
Let s1 be the driven spindle with unknown angular velocity omega1, unknown angular acceleration alpha1

Find:
What is the linear velocity V of the tape at any given time, t?
What is the angle of AB relative to the x-axis, call this angle, gamma, at any given time, t?
What is the angular velocity omega1?
What is the angular acceleration alpha1?
What is the rate of change of R1 at any time, t? (dR1/dt)
What are the radii R1 and R2 at any given time t?
What is the total time, T, to unwind the entire tape?
How many clockwise REVOLUTIONS (or if you prefer, radians), N2, will it take s2 to completely unwind s1? Call the angle subtended by s2 in any given time t, in radians, theta2.
Call the angle subtended by s1 in any given time T, in radians, theta1.

State or label other necessary assumptions or conventions.

It can be solved without going into vectors but if you are going to use vector notation, assume a xyz-coordinate system:
x-axis is positive going to the right of the page,
y-axis is positive going to the top of the page,
z-axis is positive going out of the page
using the right-hand rule of rotation, therefore, the k vector of omega2 is negative since it is clockwise
and show the vector differential equations of motion and derivation.

This is a lot harder than it seems and I haven't had the brains to solve it.

Thanks!
 
Since I don't normally post on the Tech Talk forum, kindly PM me to look up this forum if you have a way to attack the problem.

Thanks again!
 
Disregard this assumption: 'Therefore the tape leaves A tangent to R1 and enters B tangent to R2."
I might have assumed too much on that one. It needs proof that the condition of tangency is valid first.

If you guys can also point me out also on other forums that might be of help. Thanks.
 
I hate remembering enough physics to understand the question, but forgetting so much I'd have no idea where to start.
 
how about googling it?


maybe not

tried that before. although if you know or if you can point me out to a forum where i can get help, that'd be great. by the way, i've finished college years ago, i just want to brush up on my past lessons. i'm entertaining the thought of taking a masters. but i need to build up some confidence first.
 
Oh, goodness.

If it weren't 10:21 PM on a Friday night I might be able to crack this one. College physics was 10 years ago.

Cassette tapes don't quite work this way though. The tape player drives the tape at a constant velocity (pinch roller & capstan), and the spools simply keep enough tension on the tape to keep it from making a mess.
 
Back
Top