Question

A square glass plate 9.5 cm on the edge
& 0.5cm thick, is suspended in a trough containing
water so that its one
edge just touches the water surface.
Calculate the downward force due to
Surface Tension acting on the plate.
(surface tension of water = 72 dyne/cm)​

Answer 1

Given: A square glass plate 9.5 cm on the edge  & 0.5 cm thick, is suspended in a trough containing  water so that its one  edge just touches the water surface.

To find: Calculate the downward force due to  Surface Tension acting on the plate.

Solution:

• Now we have given surface tension of water = 72 dyne/cm

• The force due to surface  tension on glass plate will be:

                  F = 4lT + W

• Here W is weight of glass plate, which is:

                  W = volume × density

                  W = 108.3 g

• Now the force due to surface tension will be:

                  F = 4 × 9.5 × 72 + 108.3

                  F = 2844.3 dyne

Answer:

            So the force is 2844.3 dyne