Download the app

Questions  

A body cools in a surrounding which is at a constant temperature of θ0. Assume that it obeys Newton's law of cooling. Its temperature θ is plotted against time t. Tangents are drawn to the curve at the points Pθ=θ2 and Qθ=θ1. These tangents meet the time axis at angles of ϕ2 and ϕ1, as

Unlock the full solution & master the concept.

Get a detailed solution and exclusive access to our masterclass to ensure you never miss a concept
By Expert Faculty of Sri Chaitanya
a
tan⁡ϕ2tan⁡ϕ1=θ1−θ0θ2−θ0
b
tan⁡ϕ2tan⁡ϕ1=θ2−θ0θ1−θ0
c
tan⁡ϕ1tan⁡ϕ2=θ1θ2
d
tan⁡ϕ1tan⁡ϕ2=θ2θ1
NEW

Ready to Test Your Skills?

Check Your Performance Today with our Free Mock Tests used by Toppers!

detailed solution

Correct option is B

For θ−t plot, rate of cooling =dθdt= slope of the curve.  At  P,dθdt=tan⁡ϕ2=k(θ2−θ0), where k= constant.  At  Q, dθdt=tan⁡ϕ1=kθ1−θ0⇒tan⁡ϕ2tan⁡ϕ1=θ2−θ0θ1−θ0


Similar Questions

A body cools down from 60°C to 55°C in 30 s. Using Newton’s law of cooling, calculate the approximate time taken by same body to cool down from 5 5°C
to 50°C. Assume that the temperature of surroundings is 45°C.

Get your all doubts cleared from
Sri Chaitanya experts

counselling
india
+91

phone iconwhats app icon