A student has 25 identical flat metal washers. Describe how they can use a standard 30 cm30\text{ cm}30 cm ruler to determine the thickness of one washer accurately.
The student finds another larger washer that they suspect is made of copper. They perform an experiment to find the washer's density and obtain the following results:
Show that the density of this washer is about 8.8 g/cm38.8\text{ g/cm}^38.8 g/cm3.
The density of liquid mercury is 13.6 g/cm313.6\text{ g/cm}^313.6 g/cm3. State and explain whether the washer in (b)(i) floats on liquid mercury.
169 exam-style questions on CIE IGCSE Physics Density, covering Density. Each one has a worked solution and a mark scheme showing where the marks go.