Suppose you swing a ball of mass (m) in a vertical circle on a string of length (l). as you probably know from experience, there is a minimum angular velocity you must maintain if you want the ball to complete the full circle without the string going slack at the top.1. find an expression for the minimum angular velocity using only the terms (g) and (l).2. evaluate the angular velocity in rpm for a 65 g ball tied to a 2.0-m-long string.

First answer marked as brainiest which is the correct equation describing the first law of thermodynamics? a) when the internal energy of a system changes, it equals the amount of heat added plus the work done. b) when work is done by the piston, it is equal to the heat added plus the change in internal energy of the system. c) when heat is added to the system, it is equal to the amount of work done by the piston plus the change in internal energy of the system.