1. You point a tennis-ball serving machine straight up and put a piece of plastic wrap across the top of the barrel, placing a 10-g marble on top of the barrel. When a 58-g tennis ball in the machine is fired, it sends the marble into the air. The marble rises 210 m above the barrel mouth, and the tennis ball rises 71 m.
Neglecting the plastic wrap, what is the ball's launch speed?
Express your answer to two significant digits and include the appropriate units.