Reaction time tests can be used to assess an individual’s hand-eye coordination. One
test involves catching a 1 metre ruler and measuring the distance, d in metres, that the
ruler travelled before being caught. The reaction time t seconds is then calculated using
the formula:
? = √2d/9.8
(a) Simplify the expression
2d/9.8
under the square root sign to
d/?
(b) Calculate the reaction time if the distance the ruler fell before being caught was
40cm.
(c) Make d the subject of the equation, remembering to use your simplified version of
d/? which you found in part (a).
(d) Use your equation from part (c) to find the distance the ruler should fall before being
caught if t is half the value you found in part (b), i.e. half the time taken to catch the
ruler when it fell 40 cm.
test involves catching a 1 metre ruler and measuring the distance, d in metres, that the
ruler travelled before being caught. The reaction time t seconds is then calculated using
the formula:
? = √2d/9.8
(a) Simplify the expression
2d/9.8
under the square root sign to
d/?
(b) Calculate the reaction time if the distance the ruler fell before being caught was
40cm.
(c) Make d the subject of the equation, remembering to use your simplified version of
d/? which you found in part (a).
(d) Use your equation from part (c) to find the distance the ruler should fall before being
caught if t is half the value you found in part (b), i.e. half the time taken to catch the
ruler when it fell 40 cm.