Q.
A can is taken out from a refrigerator at 0∘C. The atmospheric temperature is 25∘C. If t1 is the time taken to heat from 0∘C to 5∘C and t2 is the time taken from 10∘C to 15∘C, then :
Sir Newton's law of heating states that rate of change of temperature of a object is proportional to the difference in temperatures of the surrounding and the object. In the given cases, when initial temperature of can is 0∘C, the difference in temperatures of can and surrounding is 25−0=25∘C.
When initial temperature of can is 10∘C, the difference in temperatures of can and surrounding is 25−10=15∘C therefore the rate of heating will be higher, when temperature difference is 25∘C i.e. time t1 will be smaller than t1<t2