Can't find the third Dragon Ball in a Mission

[Everybody do the flop]

In the mission where you have to collect 6 Dragon Balls and you fight against the Cell Jr.s, I can't find the third Dragon ball in the level! It always seems to get stuck in an out of bounds area and I can't do anything after defeating the two Cell Jr.s.

[Everybody do the flop]

So is this supposed to happen, or an I screwed?

[Tarchia]

If you fly right of a cave hugging the edge of the map you should see it on the radar somewhere you feel you can't get to. Use a Ki Blast of some sort (not sure if strikes work?) to destroy the mountain, it is under there

Edit: If you aren't sure what cave I mean, you should've fought a Cell Jr there. Not sure how else to explain where it is, just fly around hugging the edge!

[Everybody do the flop]

OK, yeah, I know the cave and I tried to destroy the mountain three times, but the game wouldn't let me, so I thought it was indestructible.

[Tarchia]

You can see the dragon ball on your radar? Worked for me when I tried...

https://www.youtube.com/watch?v=yDxHn8VoS5c&feature=youtu.be&t=5m44s He collects the dragon ball about 5 minutes in, dunno when he destroys it exactly but to see where.

[Benz]

the mountains you were talking about, just use strong ki blasts on it, like kamekameha. the cave will break down and just fly in to that.

It took me 3 tries to figure out this thing