Menu div.question,div.steps {font-size: 16px; padding: 10px;line-height: 20px; margin: 20px;} div.question{border: 1px solid #ccc;} div#solution .button{font-size: 20px; margin: 20px; width: 200px; padding: 10px; text-align: center;} div.hint,div.answer,div.steps{display: none;} div.pre_next{font-size: 30px; width:90%; margin:auto;} div.pre_next a.nav_pre{float:left;} div.pre_next a.nav_next{float:right;} div.title div.notes{ font-family:sans-serif, Arial; font-size: 18px; } 2. An automobile company displays a die-cast model of its first car, made from 9.35 kg of iron. To celebrate its hundredth year in business, a worker will recast the model in solid gold from the original dies. What mass of gold is needed to make the new model? Given: Density of iron: ρ_i = 7.86 times 10^3 kg//m^3 Density of gold: ρ_g = 1.93 times 10^4 kg//m^3 Hint The volume of both models are same, ρ=m/V Answer 23.0 kg Show Steps From ρ=m/V we get V = m/ρ Since volume of iron model and gold model are same: V_i = V_g m_i/ρ_i =m_g/ρ_g m_g = m_i(ρ_g/ρ_i) =(9.35 kg)((1.93 times 10^4 kg//m^3)/(7.86 times 10^3 kg//m^3)) = 23.0 kg