Question

you have a graduated cylinder, which is filled with water up to 150 ml mark. you add a hunk of iron, and the water level rises to 425 ml. what is the volume of the piece of iron? *
options: 150, 2160, 275, 425, 7.87
you have a graduated cylinder, which is filled with water up to 150 ml mark. you add a hunk of iron, and the water level rises to 425 ml. what is the mass of the iron? (the density if iron is 7.87 g/cm^3) *
options: 425, 150, 275, 7.87, 2160

Explanation:

First Sub - Question (Volume of Iron)

Step1: Recall displacement method

The volume of the iron is the difference between the final and initial water volume. Initial volume \( V_i = 150\space mL \), final volume \( V_f=425\space mL \).

Step2: Calculate volume of iron

Volume of iron \( V = V_f - V_i=425 - 150 = 275\space mL\) (since \( 1\space mL = 1\space cm^3 \), volume in \( cm^3 \) is also 275).

Step1: Recall density formula

Density formula is \(
ho=\frac{m}{V} \), so \( m=
ho\times V \). We know \(
ho = 7.87\space g/cm^3 \) and \( V = 275\space cm^3 \) (from first sub - question).

Step2: Calculate mass

\( m=7.87\times275 = 2164.25\approx2160\space g \) (the slight difference is due to rounding).

Answer:

275

Second Sub - Question (Mass of Iron)