That's interesting - almost counter-intuitive. I would conjecture that the colder liquid would help cool down the new hot coffee so that it doesn't melt as much ice.
Hello - first post to PF. I was making my iced coffee this morning as usual by pouring hot, freshly brewed coffee atop a large cup of ice. I then began to wonder about the thermodynamics of this situation. Will the dV/dt (V=volume, t=time) affect how quickly the ice melts? As I pour in the...