The difference in temperature between a hot pie and its surroundings decreases by 4% every minute. A hot pie bought at a Broncos-Canberra game starts at a temperature of 72 degrees celcius,while the temperature at the ground is 15 degrees. It takes 3 minutes to walk back to the stand......

Question

anonymous · Answer

if that's too hard i'll get another one

kropot72 · Answer

The temperature of the pie after 3 minutes is given by:
$$\large [(72-15)\times0.96^{3}]+15=you\ can\ calculate$$

anonymous · Answer

wow... could you please explain that step by step if you don't mind...

anonymous · Answer

@kropot72

kropot72 · Answer

First we need to find the initial temperature difference between the hot pie and the surroundings, which is simply 72 - 15 = 57 degrees. We are given that the temperature difference decreases by 4% every minute, therefore the temperature difference after 1 minute will be 57 * 0.96. The temperature difference after two minutes will be:
 57 * 0.96 * 0.96, and after 3 minutes will be 57 * 0.96 * 0.96 * 0.96.
When we have found the temperature difference after 3 minutes, we then need to add the temperature at the ground, 15 degrees, to find the temperature of the pie after 3 minutes.