ruler drop test

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A simple test of response time in which the subject attempts to stop a falling ruler. The distance the ruler drops is converted into response time using the formula: d = ut + 1/2.at², where d is the distance the ruler falls in centimetres, u is the initial velocity of the ruler (if static at the start time, this will be zero), t is the response time in seconds, and a is the acceleration of ruler due to gravity constant (i.e. 981 cm s⁻¹).