Kevin Zhou — USAPhO Practice B Problem 1 · Kevin Zhou #USAPhOB.1
Physics · electromagnetism
Problem
At time t = 0, the mass has speed v in the tangential direction along the dotted circle of
0
radius R shown. You pull on the string so that the mass keeps moving along the dotted circle,
so that the string remains in contact with the pole at all times. Find the speed of the mass
as a function of time.