A steel block has mass $40 \mathrm{g}$. It is in the form of a cube. Each edge of the cube is $1.74 \mathrm{cm}$ long. Calculate the density of the steel.

A student measures the density of a piece of steel. She uses the method of displacement to find its volume. Her measurements are shown in the diagram. Calculate the volume of the steel and its density.

A pendulum is timed, first for $20$ swings and then for $50$ swings.

time for $20$ swings$=17.4 \mathrm{s}$

time for $50$ swings$=43.2 \mathrm{s}$

Calculate the average time per swings in each case, The answers are slightly different. Suggest some possible experimental reason for this.

To find the the density of a substance, we need to measure the mass and volume of a sample of the substance. Write the equation that links there three quantities.

To find the density of a substance, we need to measure the mass and volume of a sample of the substance. The units of density depend on the units we use when measuring mass and volume. Copy and complete the table to show the correct units for density.