An experiment was done to determine a student's reaction time. Student A placed a meter stick between two of Student B's fingers. Student A called out when she let go of the meter stick. Student B caught the meter stick. Calculate reaction time?

1 Answer
Oct 21, 2014

#t = sqrt((2d)/g)#

Explanation:

The equation to determine your reaction time is derived from the kinematic formula:

#d##= ##1/2*g*t^2#,

where:

#d# = the distance the meter stick fell, in meters (divide cm by 100)
#g# = the acceleration of gravity, #"9.81 m/s"^2#
#t# = the time the meter stick fell, in seconds

To derive the formula for determining reaction time from the previous equation:

#1)# multiply both sides times 2;

#2*d=cancel2*1/cancel2*g*t^2#

#2d=g*t^2#

#2)# divide both sides by #g#;

#(2d)/g=cancelg*t^2/cancelg#

#3)# take the square root of both sides.

#sqrt((2d)/g)=t#

Switch sides.

#t=sqrt((2d)/g)#