Question

Logs sometimes float vertically in a lake because one end has become water-logged and denser than the other. What is the average density of a uniform-diameter log that floats with 29.1 % of its length above water?

Answer 1

Answer:

709 kg/m³

Explanation:

Applying the expression obtained from Archimedes Principle as:

$\% of\ the\ fraction\ submerged=\frac {\rho_{object}}{\rho_{liquid}}\times 100$

Given :

Percentage of the log above water = 29.1%

Percentage of the log of the water submerged = 100-29.1 % = 70.9%

Density of water = 1000 kg/m³

So,

$70.9 \% =\frac {\rho_{object}}{1000}\times 100$

The average density of the log = 709 kg/m³