Can you knit a jumper with just half a kilometre of wool?
It depends on the size and style of jumper you want, the stitch pattern being used, and the weight of yarn you have. A large sweater with a dense stitch pattern (such as lots of cables) will require more yarn than a small sweater with a lace pattern. You can knit further with a finer weight of yarn (say a sport weight instead of a worsted weight).
