Question

A thin liquid film formed between a U- shaped wire and a light slider supports and weight of 1.5 × 10-2N. The length of the slider is 30 cm and its weight negligible. The surface tension of the liquid film is :

Answer 1

see the attachment

Explanation:

The force of surface tension acting on the slider balances the force due to the weight.

⟹F = 2T/= w

$= >2T(0.3) = {1.5 \times 10}^{ - 2}$

$= >T =2.5 \times {10}^{ - 2}$

$= >T =0.025 Nm$