Giulia unreels her kite string until the kite is flying on a string of length 50 m. A light breeze holds the kite such that the string makes an angle of 60° with the ground. After a few minutes, the wind picks up speed. The wind now pushes the kite until the string makes an angle of 45° with the ground. What distance has the kite changed position horizontally over the ground. Determine an exact expression.