# Homework Help: Finding Velocity at which mass being spun on string will bre

1. Feb 13, 2016

### Nikki1357

This is a question for the setup of a lab. I understand that the string must be tied to the mass and then spun in an overhead circle. A cylindrical tube with non-sharp edges will be used to spin the mass. Then, the string will be pulled through the mass, which would reduce the radius and consequently cause the velocity to increase. At one point the string would break. Since the radius at which the string broke is known and the time can be found the velocity could be found, provided the acceleration was known. Velocity=acceleration*times. What is the most efficient method to find acceleration? Can I assume there is a constant angular acceleration because it is traveling the same circle in the same amount of time? But will it change because the radius of the circle in smaller? I have a good understanding of F=mv^2/r and F=mw^2r. I also understand that the force of tension is the centripetal force that is acting inward and causing the acceleration. I just don't understand how to collect data to determine what velocity the mass was spinning at when the string broke. Please help!

Last edited by a moderator: Feb 13, 2016
2. Feb 13, 2016

### Nikki1357

Sorry I meant the string will be pulled through the tube that is being used to spin the mass.

3. Feb 13, 2016

### Staff: Mentor

It is very hard to help you when you delete the Homework Help Template when you post here asking for help. Could you please re-post using the HH Template?

4. Feb 13, 2016

### Nikki1357

Sorry I'm a little confused on using this website. I reposted using the right format on a new thread. I apologize for bumping! I didn't understand what that meant.

5. Feb 13, 2016

### Staff: Mentor

The Template has three sections. The Problem Statement, the Relevant Equations, and your Attempt at the Solution. Can you re-organize your post to fill out those three sections?