Creating a falling ball map
Pyth, 19 bytes
VQ.>+*\_25*d5O30*b4
Try it here!
Explanation
VQ.>+*\_25*d5O30*b4 # Q = input VQ # Repeat Q times *\_25 # 25 underscores *d5 # 5 spaces + # concat the underscores and spaces .> O25 # rotate this string 0-29 times *b4 # print the seperating newlines
Ruby, 74 71 59
Thanks to Alex A. for reminding me that being basically one line means I can use the stabby lambda
f=->n{n.times{puts (('_'*25+' '*5)*2)[rand(30),30]+"\n"*5}}
Pyth, 19 bytes
VQ.>r"5 25_"9O30*4b
Try it here
Thanks to FryAmTheEggman for catching a bug.