A rectangular frame having dimensions of 5 cm xx 3 cm xx 3 mm is placed vertical in such a way that its longest side just touches the water surface. What will be the downward force acting on the frame? Surface tension of water is 0.72 Nm^(-1).

A rectangular frame having dimensions of 5 cm xx 3 cm xx 3 mm is place

1.	A rectangular frame having dimensions of 5 cm xx 3 cm xx 3 mm is placed vertical in such a way that its longest side just touches the water surface. What will be the downward force acting on the frame? Surface tension of water is 0.72 Nm^(-1).
Answer» Solution :T=surface tension FORCE `=T XX 2 ("LENGTH+ THICKNESS")` `=0.072 xx 2(5 xx 10^(-2) +3 xx 10^(-3))` `=0.144 (0.05+0.003)` `=0.007 or 7 xx 10^(-3)N`