To the nearest second, what is the earliest time after midnight (excluding 00:00:00) that the minute hand and hour hand are precisely on top of one another?
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Firstly, note that the first time the hands cross after 00:00:00 will come between 1 'o' clock and 2 'o' clock. Hence, we can take 1 'o' clock as a starting point in any calculations of distance travelled by the hands.
The hour hand moves at a rate of 5 x / h r , where 1 x is an increment of 1 minute of the clock. Meanwhile, the minute hand moves at a rate of 6 0 x / h r . However, since we already know that the point of overlap comes after 1 'o' clock, we can simplify the problem by immediately giving the hour hand it's 5x headstart: see the picture attached if this isn't clear.
v = d / t , so using these previously calculated "rates", we can formulate expressions for the distance travelled by each hand. The hour hand's distance (i.e. number of increments) from the 1 'o' clock position is given by 5 t + 5 whereas the minute hand's position is given by 6 0 t . These can be solved simultaneously: 6 0 t = 5 t + 5 5 5 t = 5 t = 5 5 5 = 1 1 1 So the hands overlap at 1 1 1 of a minute - 27 seconds - after 01:05:00. So the solution is 0 1 : 0 5 : 2 7 .