A rectangular plate of dimension `6 cm xx 4cm` and thickness `2mm` is placed with its largest face flat on the surface of water. Find the downward force on the plate due to surface tension. Surface tension of water is `7.0 xx 10^(-2)Nm^(-1)`.A. `1.8 xx 10^(-2)N`B. `1.4 xx 10^(-2)N`C. `2 xx 10^(-2) N`D. `2.5 xx 10^(-2) N`

A rectangular plate of dimension `6 cm xx 4cm` and thickness `2mm` is

1.	A rectangular plate of dimension `6 cm xx 4cm` and thickness `2mm` is placed with its largest face flat on the surface of water. Find the downward force on the plate due to surface tension. Surface tension of water is `7.0 xx 10^(-2)Nm^(-1)`.A. `1.8 xx 10^(-2)N`B. `1.4 xx 10^(-2)N`C. `2 xx 10^(-2) N`D. `2.5 xx 10^(-2) N`
Answer» Correct Answer - B Given, `l = 6 xx 10^(-2)m`, `b = 4 xx 10^(-2)m`, `d = 2 xx 10^(-3) m`, and `S = 7.0 xx 10^(-2) Nm^(-1)` Force on the plate due to surface tension is `F = 2(l+b)S` `= 2(6 xx 10^(-2) + 4 xx 10^(-2)) xx 7.0 xx 10^(-2)` `= 1.4 xx 10^(-2) N`

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