Angular Momentum of Ice Skater: 881.93kg m2/s

Click For Summary

Homework Help Overview

The problem involves calculating the initial angular momentum of an ice skater who is rotating while holding onto a rope attached to a pole. The skater's mass and the length of the rope are provided, along with the time taken for one complete revolution.

Discussion Character

  • Exploratory, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the calculation of angular momentum, including the moment of inertia and angular velocity. There are questions about the accuracy of the angular velocity calculation and the potential for rounding errors in the results.

Discussion Status

Some participants are exploring the calculations made by the original poster, with one suggesting a possible rounding error. Others are questioning the method used to derive angular velocity and providing alternative calculations. The discussion is ongoing, with no clear consensus reached yet.

Contextual Notes

Participants are working within the constraints of the problem statement and are focused on verifying calculations without providing a definitive solution. There is an emphasis on understanding the steps taken in the calculations.

joebob
Messages
3
Reaction score
0

Homework Statement


An ice skater with a mass of 55.5kg is holding on to the end of a 3.75 m long rope tha is attached to a pole protruding out of a frictionless ice covered pond. Intially the skater is making one revolution every 5.44seconds.
What is the initial angular momentum of the skater?

A) 780kg m2/s
B) 901kg m2/s
c) 11,200 kg m2/s
d) 18600 kg m2/s

Homework Equations





The Attempt at a Solution


I have found the moment of interia, which i found to be 780.47kg m2
I found the angular velocity to be 1.13rad/s
The answer i get is not one of the options. I get 881.93kg m2/s

 
Physics news on Phys.org
It's just a rounding error.
 
What step is my error in? i have been redoing to equations and keep getting the same
 
Angular velocity is more like 1.15 rads/sec. How did you get 1.13? 1 rev=2*pi, and 2*pi/5.44=1.155 rad/sec
 
i did x/1=1/5.44 to get .18revolutions a second and then multiplied that by 2pie to convert to radians a second
i found my error while doing this it was a rounding error thanks for the help
 

Similar threads

  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 16 ·
Replies
16
Views
4K
  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 14 ·
Replies
14
Views
3K
Replies
2
Views
5K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
9
Views
3K
  • · Replies 2 ·
Replies
2
Views
5K
  • · Replies 7 ·
Replies
7
Views
5K
  • · Replies 4 ·
Replies
4
Views
2K