Question

A thief is trying to escape from a parking garage after completing a robbery, and the thief's car is speeding toward the door of the parking garage (see figure). When the thief is L = 31 m from the door, a police officer flips a switch to close the garage door. The door starts at a height of 2.2 m and moves downward at 0.18 m/s. If the thief's car is 1.6 m tall, what should be the minimum speed of his car to escape?