when the angle of contact is greater than 90 degree how is it possible that force of cohesion is greater trhan force of adhesion?
2007-01-06 23:48:48 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Physics
The angle of contact can be greater than 90, for example take mercury in a tube, the angle of contact is greater than 90, around 120. the angle of contact is such that in equilibrium the surface makes with the wall of the tube, depeding upon the forces acting on the tiny element near the wall.
2007-01-06 23:57:30 · answer #1 · answered by Smart prash 2 · 1⤊ 0⤋
The angle of contact is the result of the cohesive and adhesive forces.
If the cohesive force is equal to the adhesive force the angle of contact is 90 degree.
In the case of silver and pure water, the angle of contact is 90
degree. The surface of water is perpendicular to the silver surface.
If the cohesive force is less than the adhesive force. the angle of contact is less than 90 degree. Glass and water.
The meniscus formed inside a tube is concave.
If the cohesive force is greater than the adhesive force, the angle of contact is more than 90 degree. Mercury and glass.
The meniscus formed inside a tube is convex.
2007-01-07 09:18:54 · answer #2 · answered by Pearlsawme 7 · 0⤊ 0⤋
when it goes beyond 90 degrees the impact reduces thats why the adhesion force decreases
2007-01-07 14:59:59 · answer #3 · answered by The Prince of Egypt 5 · 0⤊ 0⤋
well, as the above answer says, do ur homework urself...
in any case, if i ever read during my old days, i KNOW 4 sure dat ur question IS sensible.
ask ur teacher
2007-01-07 07:59:17 · answer #4 · answered by probable_oops 2 · 0⤊ 1⤋