Physics · 2014
JEE Main · 11 April 2014, Shift 1 · Q11
A hot body, obeying Newton's law of cooling is cooling down from its peak value 80°C to an ambient temperature of 30°C. It takes 5 minutes in cooling…
A hot body, obeying Newton's law of cooling is cooling down from its peak value $\displaystyle 80$°C to an ambient temperature of $\displaystyle 30$°C. It takes $\displaystyle 5$ minutes in cooling down from $\displaystyle 80$°C to $\displaystyle 40$°C. How much time will it take to cool down from $\displaystyle 62$°C to $\displaystyle 32$°C ?
(Given $\displaystyle \ln 2=0.693, \ln 5=1.609$ )
Official answer
(2)
8.$\displaystyle 6$ minutes
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JEE Main 2014 Physics question, with the answer from NTA’s final answer key. Where our answers come from.