Uniform Circular Motion Problem. Help

[aki_23]

Homework Statement

A stone tied to a string with length 1.10 m is whirled in a circle both horizontally and vertically with the same constant speed. In the vertical case the maximum tension in the string is 15.0% larger than the tension that exists when the string was horizontal. Determine the speed of the stone.

Homework Equations

a = v2/r

The Attempt at a Solution

for horizontal, my equation was Fc = mv2/r

for vertical, my equation was Fc = Ft - mg, because at the bottom of the vertical circle fg is present
mv2/r = 0.15Ft - mg

I don't know how to take this further

 

[haruspex]

Consider the horizontal case in more detail. There are vertical forces too. You should be able to find a relationship between the speed, the string length, and the tension.