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

Eight drops of water, each of radius 2 mm are falling through air at a terminal velocity of 8cms1. If they coalesce to form a single drop, then the terminal velocity of combined drop will be:

A
32cms1
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
B
30cms1
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
28cms1
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
24cms1
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is A 32cms1
Let the radius of bigger drop is R and smaller drop is r then
43πR3=8×43×πr3

or R=2r ....(i)

Terminal velocity,
vt=29r2(ρσ)gη
vtr2

vv=R2r2=(2rr)2=4 (Using (i))

or v=4v=4×8=32cms1

flag
Suggest Corrections
thumbs-up
1
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Viscosity
PHYSICS
Watch in App
Join BYJU'S Learning Program
CrossIcon