so When S is equal to 211
S = 16t^2 + 32t
211 = 16t^2 + 32t
Then, turn into a quadratic equation
0= 16t^2 + 32t - 211
Afterwards, simply find the roots of the equation by using your calculator formula 01.
you will be getting two answers,
t = 2.7666.... (correct to 3 significant figures)
t = -4.7666...(reject this because of its negative sign)
therefore, it will take 2.78 for the ball to fall 211 feet.