Question 1003210
In order to not overload the tutors, you must list these one at a time.
I will do the first one, but relist the others separately.
You can use the formula
Vf^2 - Vo^2 = 2ax
Here your final velocity, Vf = 0, the a = -15, and x = 16.
Plugging in we get
0 - Vo^2 = 2(-15)(16)
-Vo^2 = -480 so that
Vo = 21.9 m/s