Will you please provide an answer and a clear explanation?

10. (3.6:#39) Matching heights A stone is thrown with an initial velocity of 32 ft / s from the edge of a bridge that is 48 ft above the ground. The height of this stone above the ground I seconds after it is thrown is !) = 1612 + 32: + 48. If a second stone is thrown from the ground, then its height above the ground after 1' seconds is given by g(t) = - 16!2 + vat, where v0 is the initial velocity of the second stone. Determine the value of 120 such that both stones reach the same high point