When a razor blade is made to float on water, three forces act on the blade :
(i) Weight of the blade acting vertically downwards.
(ii) Reaction on blade exerted by the liquid surface
acting vertically upwards.
(iii) Force of the surface tension on circumference of the blade acting tangentially to the liquid surface. 1 In this case, as no portion of razor blade is immersed in water, hence Archimede’s principle is not applicable