Question

Heya Guyzz..!! Guddy Morning to All.. :) Here is my question.. Please answer it quickly../\ /\

If a hot body cools down from 80° to 60° in 5 minute, then what is the temperature of the hot body of that 5min? (temperature of the surrounding=20°C)

Answer 1

Answer:

Good morning

I don't know the answer because I am in 9th standard

Answer 2

$\mathfrak{\huge{\pink{\underline{\underline{AnSwEr:-}}}}}$

Here,

Initial temperature ( Ti) = 80°C

Final temperature ( Tf) = 50°C

Temperature of the surrounding ( To) = 20°C

t = 5 min

A/C to Newton's law of cooling

Rate of cooling ( dT/dt) = K[ (Ti+Tf)/2 - To]

( Tf - Ti)/t = K[ ( 80 + 50)/2 - 20]

( 80-50)/5 = K[ 65 - 20]

6 = K× 45

K = 6/45 = 2/15

in second condition,

initial temperature ( Ti) = 60°C

Final temperature ( Tf) = 30°C

Time taken for cooling is t

A/C Newton's law of cooling

( 60 - 30)/t = 2/15 [ (60+30)/2 -20]

30/t = 2/15 × 25

30/t = 50/15 = 10/3

t = 9 min