Impact is your default nano power (). A good location to get this achievement is on level 11 after the cutscene where one of your chasers gets killed and you have to kill some enemies. There is a cliff here. Position yourself so that the enemy will go flying off of the cliff and this will add a lot of distance. It may take a couple of seconds to unlock because of the long fall, but within a few tries it should unlock. You could do this with any cliff, high up place, or any open place as long as the enemy doesn't hit an object.