written 5.8 years ago by | • modified 4.5 years ago |
Specific gravity of gold is 19.3 and that of copper is 8.9.
written 5.8 years ago by | • modified 4.5 years ago |
Specific gravity of gold is 19.3 and that of copper is 8.9.
written 5.8 years ago by |
Data: m$_{air}$=36 gm
m$_{water}$=34 gm
specific gravity of gold=S$_{gold}$=19.3
specific gravity of copper=S$_{copper}$=8.9
∴ Weight of ornament in air is=W$_{air}$=$36 \times 10^{-3} \times 9.81$=0.35316 N
∴ Weight of ornament in water is=W$_{water}$=$34 \times 10^{-3} \times 9.81$=0.33354 N
Buoyant force=$F_{B}=W_{air}-W_{water}$=0.01962 N
Weight of the fluid displaced $(F_{B})=W_{water} \times $volume of the ornament
0.01962=9810$\times $volume of the ornament
∴ Volume of the ornament=$2 \times 10^{-6} m^{3}$
But, the ornament contains gold and copper
∴ Volume of the ornament (V) = $V_{gold}+V_{copper}$ ---------------(1)
$V_{gold}=\cfrac{\text{Weight of gold}}{W_{gold}}$
$V_{gold}=\cfrac{\text{Weight of gold}}{19.3 \times 9810}$
Similarly,
$V_{copper}=\cfrac{\text{Weight of copper}}{W_{copper}}$
$V_{copper}=\cfrac{\text{Weight of copper}}{8.9 \times 9810}$
Equation (1) becomes,
$2 \times 10^{-6}$= $V_{gold}+V_{copper}$
$2 \times 10^{-6}$=$\cfrac{\text{Weight of gold}}{19.3 \times 9810} + \cfrac{\text{Weight of copper}}{8.9 \times 9810}$ ---------------(2)
Also, weight of the ornament (V) = $W_{gold}+W_{copper}$=0.35316 ---------------(3)
Solving equation (2) and (3) we get,
$W_{gold}$=0.33133 N and $W_{copper}$=0.0218 N