WAEC - Physics (1998 - No. 4)
A rectangular block of wood floats in water with two-thirds of its volume immersed. When placed in another liquid, it floats with half of its volume immersed. Calculate the relative density of the liquid
1.43
1.33
1.00
0.83
0.75
Explanation
from the first statement, mg = \(\frac{2}{3}Vp_wg\) ........................1
from second statement, mg = \(\frac{1}{2}Vp_lg \)...................2
equating equations 1 and 2 we have that
\(\frac{2}{3}Vp_wg\) = \(\frac{1}{2}Vp_lg\)
\(\frac{4}{3} = \frac{p_l}{p_w}\)
= 1.33