1. The problem statement, all variables and given/known data If an object is hanging by a thread, how fast must it be twirled around in order to break the thread? (must also provide explanation of why this is the velocity). As a part of a lab, pick a certain mass. Attach to light string (easily breaks) and pull the string through a cylindrical tube with blunt edges that won't cut the string. Spin mass in circle and reduce the radius, thus increasing the velocity, until mass breaks. 2. Relevant equations F=mv^2/r F=mw^2r v=vo+at v=wr v/r=w 3. The attempt at a solution If videotaped I know I can find the radius. I will be able to weigh a mass. I need help understanding the quickest way to measure acceleration. If I know the acceleration my plan it to time it to find when the mass breaks off and then use the 3rd equation from above to solve for the velocity (knowing it starts from rest).