A very light, rectangular wire-frame of dimensions 7cmx 5 cm hangs just above the free surface of a liquid of surface tension T, with its plane parallel to the free surface. The wire-frame is just brought in contact with the liquid surface and then, lifted up. If the force required to lift the wireframe is 3. 36 N, then what is the value of T (in N m -1 )?
Text Solution
Verified by ExpertsCHECK THE SOLUTION.
(7)
The downward force of surface tension acting on the wire frame is
F surface tension = T x 
,
where 
is the total length of the wire which is in contact with the liquid.
Now since it is a wire frame, the free surface of the liquid will be in contact with the inner as well as the
outer perimeter of the wire.
Hence, 
= 2 x 2 x (7 + 5) = 48 cm
T = 7 N m -1
Prepare Smarter with CGP Edu
Get practice questions, solutions, and test series in one place.
Write a Review
Share your experience with this question and solution.
Commentary
Send your comment, doubt, correction, or feedback to admin.
Similar Questions
Explore conceptually related problems