Answer
Greater than 8 km/s.
Work Step by Step
8 km/s is the required speed for a Newton's cannon on Earth (page 190).
Jupiter has a stronger gravitational pull than Earth, which increases the necessary speed, because the cannonball would drop a greater distance in the same time. Moreover, because Jupiter is much larger, the ground is closer to being flat, so the cannonball would have to be fired much faster so that it "falls around Jupiter".
A quantitative analysis shows that the required speed of Newton's cannon is the escape speed of the planet divided by $\sqrt{2}$, so Table 10.1 also confirms the answer.
