Question

The weight of a certain crown in air was found to
be 14 N and its weight in water is 12.7 N. Was it
[if R.D of gold is 19.3, Xwater = 9.81 kN/m3]
(a) Pure gold (b) Not pure gold
(c) Data insufficient (d) Data inconsistent
Match the list with Liat u​

Answer 1

Pure gold (b) Not pure gold

Answer 2

Crown is not of pure gold.

Explanation:

Weight of crown in air $\left(w_{a}\right)=14N$

Weight of crown in water $\left(w_{w}\right)=12.7 \mathrm{~N}$

$w_{a}$-Bouyanct Force=$w_{w}$

$\frac{r_{\text {crown }} \times v}{r_{\text {water }}}-\frac{r_{\text {water }} \times v}{r_{\text {water }}}=\frac{12.7}{r_{\text {water }}}$

$S \cdot G \times V-V=\frac{12.7}{r_{\omega}}$

$S G-1=\frac{12 \cdot 7}{r_{\omega} \times V}$

$r_{w} \times v=\omega_{a}-w_{w}=14-12.7=1.3 \mathrm{~N}$

$S G=\frac{12.7}{1.3}+1=10.77$

$Crown < Gold\\10.77 < 19.3$