How maths reveals the very best time so as to add milk for warmer tea

PICTURE the scene: you make a cup of tea for a buddy who’s on their means and gained’t be arriving for a short time. However – catastrophe – you have got already poured scorching water onto a teabag! The query is, when you don’t need their tea to be too chilly once they come to drink it, do you add the chilly milk immediately or wait till your buddy arrives?

Fortunately, maths has the reply. When a scorching object like a cup of tea is uncovered to cooler air, it would calm down by dropping warmth. That is the …