A cannonball of mass 15 kg is fired vertically upward from a cannon with an initial speed of 20 m/s. The cannonball travels upward, reaches a maximum height of 40 m, and returns to the ground. Now you decide to shoot a 30 kg cannonball vertically upward using the same cannon. If we assume that all cannonballs leave this cannon with an initial speed of 20 m/s, what maximum height does the 30 kg cannonball reach

30kg ball will have equal traveling height with the 15kg

Explanation:

When air resistance is negligible, the mass of the object does not affect the maximum height or the time spent in the air.

So if mass does not affect traveling height when sir resistance is neglected...the 30kg ball will have equal traveling height with the 15kg ball provided they have equall velocities and equal angle if projection.

In this case it has 20 m/s and they are all projected vertically.

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.

i believe the answer is a hope it and is correct