a ball is at rest on a platform and falls freely, hitting the ground in 1.1 seconds. What is the height of the platform?
xf = xo + vo t + 1/2 at2 (I used x as a matter of convention.....but you can switch them to 'y' )
xf = final height= the ground = 0
xo = intitial position (what we are looking for)
vo = original velocity = 0
a = accelaration of gravity choose either -32.2 ft/s2 your answer will be in feet
or choose -9.81 m/s2 your answer will be in meters
t = time = 1.1 (given) Plug in the numbers and calculate.....