String is wrapped around an object of mass 1.2kg, radius 0.06m, and moment of inertia 0.0015kg*m^2(the density of the object is not uniform). With your hand you pull the string straight up with some constant force F such that the center of the object does not move up or down, but the object spins faster and faster. a.) Initially the object has an angular speed w0=12rad/s. After a time interval of 0.1s, what is the angular speed w of the object?
b.) Your answer must be numeric and not contain the symbol F. Explain the physics principles you are using.