Precession Period: Calculate Speed

In summary, the conversation discusses a problem involving a wheel with given dimensions and an unknown speed. The formula used to solve the problem was found on Wikipedia and the resulting answer was questioned for its likelihood. The conversation also mentions the conversion of units and discusses an alternative method for finding the speed without using the internet.
  • #1
goonking
434
3

Homework Statement


upload_2015-4-23_23-12-37.png


Homework Equations


upload_2015-4-23_23-13-22.png

this was a formula I just found on Wikipedia, but it seemed to be right for this problem.

The Attempt at a Solution



so we have the diameter of the of the wheel = 0.7 m

mass of wheel = 0.25 kg

distance of the rod attached = 0.2m

angular velocity of wheel converted to radians = 27 rad/s

moment of inertia for wheel = m r2

Ts = is the period of of the wheel

Tp is what we are solving for.
which comes out to be 639.7 seconds. if my math is correct. but this answer seems extremely unlikely

so the wheel moves to the left, but how can I figure out the speed at which it moves at?
 
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  • #2
What are you substituting for r in the Wiki formula? What do you have for Ts?
 
  • #3
haruspex said:
What are you substituting for r in the Wiki formula? What do you have for Ts?
r should be the length of the rod, which is 0.2m.

and Ts is 1/258 = 0.00387 seconds per revolution.

correct?
 
  • #4
goonking said:
r should be the length of the rod, which is 0.2m.

and Ts is 1/258 = 0.00387 seconds per revolution.

correct?
The wheel's rotation rate is given as 258 revolutions per what?
 
  • #5
haruspex said:
The wheel's rotation rate is given as 258 revolutions per what?
minutes, oh no! i forgot to convert
 
  • #6
goonking said:
minutes, oh no! i forgot to convert

new answer comes out to be 10.7 seconds, which is sounds reasonable
 
  • #7
goonking said:
new answer comes out to be 10.7 seconds, which is sounds reasonable
Yes, it does.
 
  • #8
haruspex said:
Yes, it does.
ok, let's say i had no access to the internet, and I had no way of finding that formula, how would I then find the speed at which the wheel moves to the left?
 

What is precession period?

Precession period refers to the time it takes for an object to complete one full rotation around its axis.

How do you calculate precession period?

The precession period can be calculated by dividing the total time of rotation by the number of rotations completed.

What is the unit of measurement for precession period?

The unit of measurement for precession period is typically in seconds, but it can also be measured in minutes, hours, or any other time unit.

What factors can affect the precession period?

The precession period can be affected by a number of factors, including the mass and shape of the object, the distance from the axis of rotation, and external forces such as gravity.

Can the precession period change over time?

Yes, the precession period can change over time due to various factors such as changes in the object's mass or external forces acting upon it.

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