Particle Launched over 13.7m Gorge - Speed & Angle Calculation

[7yler]

A particle is launched over a gorge that is 13.7 m straight across and 100 m deep. The particle is launched at an angle of 14° above the horizontal, and lands with 1.7 m to spare.
What was the particle's launch speed?
If the particle was launched at a different angle, but fell 0.5m short, what would it's launch angle be?

For the first part, I figured that the launch speed should be x, where x*cos(14 deg) = 15.4 m, so x = 16 m/s, but this is not correct. Why?

 

[Delphi51]

I got a different answer. Your answer is wrong because gravity affects the answer and you have no g in yours. On the moon a smaller speed would suffice, while on Jupiter a very large velocity is needed.

Show your work and someone will be very happy to sort it out!

 

[7yler]

I realized what I was doing wrong. Thanks for the tip.