The method that will make sugar dissolve faster depends on several factors, such as the temperature of the milk, the agitation of the mixture, and the size of the sugar particles. Generally, increasing the surface area of the sugar and enhancing the contact between the sugar and the liquid will facilitate faster dissolution.
In the case of putting sugar in milk (method 1), the sugar particles are exposed to the liquid on all sides, allowing for efficient mixing and dissolution. However, if the milk is cold or not stirred, the process may be slower.
On the other hand, pouring milk on sugar (method 2) creates a smaller surface area of the sugar initially exposed to the liquid. This may slow down the dissolution process, as the sugar at the bottom of the pile will take longer to come into contact with the milk. However, if the milk is warm or stirred, it can help accelerate the dissolution by increasing the contact between the sugar and the liquid.
In general, if the milk is at room temperature or colder, and there is no additional mixing or stirring, putting sugar in milk (method 1) may result in faster dissolution. However, if the milk is warm or agitated, pouring milk on sugar (method 2) can lead to faster dissolution.
It's important to note that the difference in dissolution time between the two methods is likely to be minimal, and both methods will eventually result in the complete dissolution of sugar in milk.