Question

In a room where the temperature is 30^oC, a body cools from 61^oC to 59^oC is 4 minutes. The time taken by the body to cool from 51^oC to 49^oC will be:

• A. 4 minutes
• B. 6 minutes
• C. 5 minutes
• D. 8 minutes

Answer 1

Answer: (B)

6 minutes

Answer 2

Rate of cooling $\alpha$ difference in temperature

⇒

in first case

$\Delta \theta = 60 - 30 = 30$

dt = 4 minute

$\therefore$

For second case

∆θ = 50 − 30 = 20

$\therefore$