Question

While doing an experiment on plotting the temperature-time graph of hot water as it cools, we can get a good graph :
(1) only by noting the temperature of hot water every 30 seconds throughout
(2) only by noting the temperature of hot water every 1 minute throughout
(3) by noting the temperature of hot water every 1 minute to start with and every 2 minutes later on
(4) by noting the temperature of hot water every 2 minutes to start with and every 1 minutes later on

Answer 1

When hot water cools down, Initially its temperature falls at a higher rate but later the rate of fall of temperature decreases. So, in starting the temperature will fall faster but after sometime, it will fall a little slower. Hence, to plot a temperature-time graph for cooling of hot water, we have to note the temperature of hot water every 1 minute to start with and every 2 minutes later on.

Hence, the correct answer is option 4.