The answer is: " 208 g " . _____________________________________________ Explanation: __________________________________________ The formula/ equation for density is: __________________________________________ D = m / V ; That is, "mass divided by volume" ;
Density is expressed as: __________________________________________ "mass per unit volume"; in which the "mass" is expressed in units of "g" ("grams") ; and the "unit volume" is expressed in units of: "cm³ " or "mL"; _____________________________________________ {Note the exact equivalent: 1 cm³ = 1 mL }. ____________________________________________ → The formula is: " D = m / V " ; ___________________________________________ in which:
"D" refers to the "density" (see above), which is: "8.9 g/cm³ " (given);
"m" refers to the "mass" , in units of "g" (grams), which is unknown; and we want to find this value;
"V" refers to the "volume", in units of "cm³ " ; which is: "23.4 cm³ " (given); _________________________________________________ We want to find the mass, "m" ; so we take the original equation/formula for the density: _________________________________________________ D = m / V ; _________________________________________________________ And we rearrange; to isolate "m" (mass) on ONE side of the equation; and then we plug in our known/given values; to solve for "m" (mass); in units of "g" (grams) ; ___________________________________________________ Multiply each side of the equation by "V" ; ____________________________________________________ V * { D = m / V } ; to get: ____________________________________________________ V * D = m ; ↔ m = V * D ; ___________________________________________________ Now, we plug in the given values for "V" (volume) and "D" (density) ; to solve for the mass, "m" ; ______________________________________________________ m = V * D ;
m = (23.4 cm³) * (8.9 g / 1 cm³) = (23.4 * 8.9) g = 208.26 g ;
→ Round to "208 g" (3 significant figures); ____________________________________ The answer is: " 208 g " . _____________________________________________________
Explanation: This Law of Superposition is fundamental to the interpretation of Earth history, because at any one location it indicates the relative ages of rock layers and the fossils in them.
