A coin dealer offers to sell you an ancient gold coin that is 2.2 cm in diameter and 3.0 mm in thickness (A) the density of gold is 19.3 g/cm3. How much should the coin weigh if it is pure gold?

Question

festinger · Answer

2.2cm in diamter = 1.1cm in radius.
3.0mm  = 0.3 cm

volume (in cm) is then:
$$Volume=\pi*r^{2}*h=\pi*(1.1)^{2}*0.3=1.14cm^{3}$$
Thus the mass is then
$$mass=\rho*V=19.3*1.14=22g$$

anonymous · Answer

Thank you. There is a lacking question, (B) if gold sells for $640 per troy ounce, how much is the gold content worth?