Question

It is known, that the units of mass, length and time, in the SI units and FPS system, are related as

1 kg = 2.205 pound; 1 m = 3.28 feet, 1s = 1s

The value of the surface tension of water is 7.3 x10^-2 N/m. Its value, in the FPS units, would be

(1) 0.066 FPS units

(2) 0.033 FPS unit

(3) 0.16 FPS units

(4) 0.32 FPS units

Answer 1

(3) 0.16 FPS units

We have,

[Surface tension] = (Force/length) = [MLT^-2/L]

= [MT^-2]

∴ Unit of surface tension in SI units / Unit of Surface tension in FPS System

= (Kg/pound) (s/s)^-2 = 2.205 pound / 1 poind (1)^-2

= 2.205

∴ 7.3 x 10^-2 Units in SI Units = 2.205 x 7.3 x 10^-2 Units

= 16.1 x 10^-2 FPS Units

= 0.16 FPS Units