Don't know if it is a homework question or not but it was a friend asking me and I feel ashamed because I am engineer but I don't know. When whirling a supplied mass on a string in a horizontal circle with constant speed. Assume that the mass of the string is negligible compared to the mass of the object you are whirling. If you whirl the mass at a larger constant speed, you can feel a change in the force exerted on your hand by the string. If you whirl the mass at twice the initial speed, how does the forced exerted on the mass compare to the original force? And is the string perfectly horizontal? It's my first time using the forum, so if it is determined that the above is a homework question, then please let me know and I will post it over there. I just don't know the equations involved. Thanks.