A needle 5cm long can just rest on the surface of the water without wetting. What us it's weight? Surface tension is 0.007N/m
1 answer:
You might be interested in
Silver is a very good conductor, this means its resistivity is very low (from table, we can check the precise value, which is 
).
Pure water, instead, is a very bad conductor, this means its resistivity is very high, of order of
(
). Even without knowing the precise value of the pure water resistivity, we can estimate the ratio between the pure water resistivity and the silver resistivity by comparing the two orders of magnitude:
Therefore, we can say that the correct answer is
Pure water, instead, is a very bad conductor, this means its resistivity is very high, of order of
Therefore, we can say that the correct answer is