At HKUST's mosquito lake, you may find an aquatic insect called a water strider which can walk across the surface of a pond supported by surface tension. Draw a sketch that shows the forces acting on each "leg" of the insect. If each of the joints of the four large (posterior) legs of the insect that are in contact with the water surface (similar to the figure shown below) can be considered to be cylinder of radius 500 um and length 5 mm, what is the most the creature could weigh and still deserve its name? Hint: the maximum weight would occur if the angle of the meniscus is vertical.
a) 0.12 grams
b) 1.2 grams
c) 12 grams
d) 120 grams