Question

Under the right conditions, it is possible, due to surface tension, to have metal objects float on water. Consider placing a short length of a small diameter steel (sp. wt.=500 lb/ft3) rod on a surface of water. What is the maximum diameter, Dmax⁡, that the rod can have before it will sink? Assume that the surface tension forces act vertically upward. Note: A standard paper clip has a diameter of 0.036 in. Partially unfold a paper clip and see if you can get it to float on water. Do the results of this experiment support your analysis?

Answer 1

Answer:

D = 0.060732 in

Explanation:

given data

sp. wt. = 500 lb/ft³

diameter = 0.036 in

solution

we get here maximum diameter of rod that is express as

D = $\sqrt{\frac{8 \sigma }{\pi y}}$   ......................1

here $\sigma$ surface tension of water at 60⁰f  = 5.03 × $10^{-3}$  lb/ft and y = 500 lb/ft³

so put here value and we will get

D = $\sqrt{\frac{8 \times 5.03 \times 10^{-3} }{\pi \times 500}}$

D = 0.005061 ft

D = 0.060732 in