A student is investigating the impact of a solid brass sphere when it is dropped from a height on to a flat tray filled with fine flour.
The student measures the time taken for the sphere to fall through a height of 1.50 m1.50\text{ m}1.50 m on to the flour using a handheld digital stopwatch. Suggest a main cause of inaccuracy in this time measurement.
The impact of the sphere creates a circular crater in the flour. Describe how you would measure the diameter of this crater as reliably as possible. State the name of the measuring instrument you would use.
The student hypothesizes that the diameter of the crater depends on the drop height, which affects the impact velocity. Identify two other physical variables on which the crater diameter might depend.
164 exam-style questions on CIE IGCSE Physics Physical quantities and measurement techniques, covering Physical quantities and measurement techniques. Each one has a worked solution and a mark scheme showing where the marks go.