A helicopter carrying Dr. Evil takes off with a constant upward acceleration of 7.0 m/s. Secret agent Austin Powers jumps on just as the helicopter ifts off the ground. After the two men struggle for 11.0 s, Powers shuts off the engine and steps out of the helicopter. Assume that the helicopter is in free fall after its engine is shut off, and ignore the effects of air resistance. What is the maximum height above ground reached by the helicopter?