Question

The temperature of the body drops from 60°C to 40°C in 7 min. The surrounding temperature is 10°C. The temperature of the body drops from 40°C to T°C in 7 min. Find the value of T

• A. 16°C
• B. 20°C
• C. 28°C
• D. 36°C

Answer 1

Answer: (C)

28°C

Answer 2

The correct option is (C) 28°C
$\frac{(60-40)}{7}=K(50-10)$
$\Rightarrow\frac{(40-T)}{7}=K([\frac{40+T}{2}]-10)$
$\Rightarrow\frac{20}{(40-T)}=\frac{(40\times2)}{(T+20)}$
$\Rightarrow T+20=160-4T$
$\Rightarrow 5T = 140$
$T = \frac{140}{5}$
$T$ = 28°C