A ball is ejected to the right with an unknown horizontal velocity from the top of a pillar that is 50 meters in height. At the exact instant, a carriage moving on rails is also released to the right from the bottom of the pillar. Calculate the velocity with which the carriage should be released so that the ball falls in the carriage after the carriage has traveled a distance of 50 meters on the ground. A. 12.20 meters/ seconds
B. 13.23 meters/ seconds
C. 14.30 meters/ seconds
D. 15.65 meters/ seconds**
E. 16.00 meters/ seconds

I believe D is right = 15.65m/s
Also ** on Plato