A digital stop-clock displays time in minutes and seconds, updating the display only when a full second has completed (meaning fractional seconds are truncated; for example, any time from 45.0 s45.0\text{ s}45.0 s up to but not including 46.0 s46.0\text{ s}46.0 s is displayed as 00:4500:4500:45).
The stop-clock reads 00:4500:4500:45 when it is started. It reads 02:2002:2002:20 when it is stopped.
What is the shortest possible time that has passed between starting and stopping the stop-clock?
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.