A test rocket is fired vertically upward from a well. A catapult gives it initial speed 50 m/s at ground level. Its engines then fire and it accelerates upward at 5.0 m/s² until it reaches an altitude of 1,200 m. At that point its engines fail and the rocket goes into free-fall, with an acceleration of g=9.80 m/s².

What is its velocity just before it collides with the Earth? (You will need to consider the motion while the engine is operating separately from the free-fall motion.)

[ Give your answer in m/s to the nearest 0.1 m/s ]