Question: What determines the Rate of Heating of an object (the rate at which heat energy flows towards the object)?
The main factor that determines how quickly heat flows from one object to another is the size of the temperature difference between them.
The greater the temperature difference the faster an object will heat or cool.
The temperature difference is found by subtracting the temperature of the colder object from the temperature of the hotter object. It is the number of degree Celsius between the two values of temperature.