Question 122451
Answer:
t1 + t2 = (sqrt d)/4 + d/1090 ---> Equation

Since total time is t1+t2, then t1+t2 = 3.1 secs (given)
Substituting the value to the above equation, we get:

3.1 = (sqrt d)/4 + d/1090
*multiply whole eqtn by 1090 (to eliminate denominator)
--> 3379 = 272.5(sqrt d) + d
*transpose d (from right side of equation) to the left side making it negative
--> 3379 - d = 272.5(sqrt d)
*squre both sides and simplify
--> (3379 - d)2 = (272.5(sqrt d))2
--> 11417641 - 6758d - d2 = 74256.25d
*transpose right side eqtn to the left and combine like terms
d2 + 67498.25d -11417641 = 0
*Using this formula : {{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}}
You will get 2 answers, 1 positive and 1 negative. The answer is the positive value which is 169ft (rounded off)