During the design of a ski ramp, for safety it was decided that a skier should have a speed of no more than 30 m/s when reaching the bottom of the ramp. It is known that a typical 85 kg skier has a speed of 2 m/s upon leaving the starting gate at the top. Friction and resistance do 4000 J of work on the way down. What is the maximum height of the starting gate for which the maximum speed will not be exceeded?