Toy Dart Gun

Think about the question below. Only one of the answers listed is correct. We'll do some (but probably not all) of these questions in the lectures when you will all be asked to vote on which answer you think is correct. (Soon afterwards, you'll be able to see your responses, and those of the whole class at EVAF.)

A spring-loaded toy dart gun is used to shoot a dart straight up in the air, and the dart reaches a maximum height of 24 m. The same dart is shot straight up a second time from the same gun, but this time the spring is compressed only half as far before firing. How far up does the dart go this time, neglecting friction and assuming an ideal spring?
1
48 m
2
24 m
3
6 m