wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

Two bottles A and B have radii RA and RB and heights hA and hB respectively with RB=2RA and hB=2hA. These are filled with hot water at 60oC. Consider that heat loss for the bottles takes place only from side surfaces. If the time the water takes to cool down to 50oC is tA and tB for bottles A and B, respectively, then tA and tB are best related as.

A
tA=tB
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
tB=2tA
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
C
tB=4tA
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
tB=tA/2
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is A tB=2tA
From Newton's Law of cooling,
dQdt=hAΔT

Assuming, constant rate of cooling,
ΔQ=hAΔTΔt
ΔQAΔQB=AAtAABtB
mAsΔTmBsΔT=AAtAABtB
ρVAρVB=AAtAABtB
hAAAhBAB=AAtAABtB
tAtB=12
tB=2tA

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Introduction
CHEMISTRY
Watch in App
Join BYJU'S Learning Program
CrossIcon