please help

. (3 points) A bomb (mass M) thrown vertically upward from the ground (initial velocity u) explodes into three equally massive fragments as soon as it reaches the maximum height h. The fragments y in different directions. One of the fragments comes straight to the ground in a. time :1 after the explosion. The other two reach the ground at a time t; after the explosion. Find It in terms of 9, t1 and t2. 9 is the acceleration due to gravity which remains almost constant within the height h