will a single 600w cover 6ft high?

hi, im doing a vertical grow but trying to work out how many 600w's ill need, there is 8 6x4 panels so it will be a pretty large 8 sided cage, i was going to have 5 600w's on a moving circular rail which i know would be enough going around but the lights cant move up or down so a 600w would need to light 6ft high so my question is would 5x 600w in a vertical bare bulb cage be ok or would i need to double it so 1 bulb below the other so its still 5 bulbs going round but with 2 in each place.

i cant even think of the right words so above will have to do im afraid lol.

cheers guys

thats it bob you make me read some more lol