A mercury thermometer reads 10oC when dipped into melting ice and 90oC

The British gold sovereign coin is an alloy of gold and copper having a total mass of 7.988 g, and is 22-karat gold 24 x (mass o

matrenka [14]

Answers:

(a) $0.0073kg$

(b) Volume gold: $3.79(10)^{-7}m^{3}$ , Volume cupper: $7.6(10)^{-8}m^{3}$

(c) $17633.554kg/m^{3}$

Explanation:

We are told the total mass $M$ of the coin, which is an alloy of gold and copper is:

$M=m_{gold}+m_{copper}=7.988g=0.007988kg$ (1)

Where $m_{gold}$ is the mass of gold and $m_{copper}$ is the mass of copper.

In addition we know it is a 22-karat gold and the relation between the number of karats $K$ and mass is:

$K=24\frac{m_{gold}}{M}$ (2)

Finding ${m_{gold}$ :

$m_{gold}=\frac{22}{24}M$ (3)

$m_{gold}=\frac{22}{24}(0.007988kg)$ (4)

$m_{gold}=0.0073kg$ (5) This is the mass of gold in the coin

<h2>(b) Volume of gold and cupper</h2><h2 />

The density $\rho$ of an object is given by:

$\rho=\frac{mass}{volume}$

If we want to find the volume, this expression changes to: $volume=\frac{mass}{\rho}$

For gold, its volume $V_{gold}$ will be a relation between its mass $m_{gold}$ (found in (5)) and its density $\rho_{gold}=19.30g/cm^{3}=19300kg/m^{3}$ :

$V_{gold}=\frac{m_{gold}}{\rho_{gold}}$ (6)

$V_{gold}=\frac{0.0073kg}{19300kg/m^{3}}$ (7)

$V_{gold}=3.79(10)^{-7}m^{3}$ (8) Volume of gold in the coin

For copper, its volume $V_{copper}$ will be a relation between its mass $m_{copper}$ and its density $\rho_{copper}=8.96g/cm^{3}=8960kg/m^{3}$ :

$V_{copper}=\frac{m_{copper}}{\rho_{copper}}$ (9)

The mass of copper can be found by isolating $m_{copper}$ from (1):

$M=m_{gold}+m_{copper}$

$m_{copper}=M-m_{gold}$ (10)

Knowing the mass of gold found in (5):

$m_{copper}=0.007988kg-0.0073kg=0.000688kg$ (11)

Now we can find the volume of copper:

$V_{copper}=\frac{0.000688kg}{8960kg/m^{3}}$ (12)

$V_{copper}=7.6(10)^{-8}m^{3}$ (13) Volume of copper in the coin

<h2>(c) Density of the sovereign coin</h2><h2 />

Remembering density is a relation between mass and volume, in the case of the coin the density $\rho_{coin$ will be a relation between its total mass $M$ and its total volume $V$ :

$\rho_{coin}=\frac{M}{V}$ (14)

Knowing the total volume of the coin is:

$V=V_{gold}+V_{copper}=3.79(10)^{-7}m^{3}+7.6(10)^{-8}m^{3}=4.53(10)^{-7}m^{3}$ (15)

$\rho_{coin}=\frac{0.007988kg}{4.53(10)^{-7}m^{3}}$ (16)

Finally:

$\rho_{coin}=17633.554kg/m^{3}}$ (17) This is the total density of the British sovereign coin

6 0

3 years ago

Air flows upward in the wick of a lantern because of the liquid property called

vovangra [49]

Adhesive.

Adhesive is the force of attraction between molecules of different kind. Liquid flows upward the wick because the adhesive force between the wick and the liquid is higher than cohesive forces in the liquid.

When the adhesive force between the wick and the liquid is high we have capillarity taking place. This cause the liquid to move up the wick.

7 0

3 years ago

A ball of clay falls freely to a concrete floor. The ball does not bounce noticeably, and it quickly comes to rest. What has hap

omeli [17]

Answer:

The mechanical energy is converted to potential energy while the kinetic energy is zero

Explanation:

mechanical energy is the sum of potential energy and kinetic energy. It is the energy associated with the motion and position of an object. The total mechanical energy is the sum of these two forms of energy.

The Law of Conservation of Energy: Energy cannot be created or destroyed, but is merely changed from one form into another. This means that potential energy can become kinetic energy, or vice versa, but energy cannot “disappear”.

The mechanical energy is converted to potential energy while the kinetic energy is zero

7 0

3 years ago

Why do areas north of the artic circle in tje northern hemisphere experience a polar day lasting for several months during summe

adell [148]

<span>The regioin is titled towqrd the Sun during polar day. (C)

(The same exact thing happens in areas south of the Antarctic Circle
in the southern hemisphere. The only difference is that the whole thing
is spelled better in the South.)</span>

7 0

3 years ago

Read 2 more answers

Solve each of the following problems to 3 sig figs and correct Sl units, showing all work.

Salsk061 [2.6K]

Answer:

every number to 3 sf = 1) 45.0 2) 250 3) 1.30

Explanation:

your welcome :)

4 0

3 years ago