If you look at the scene carefully a couple of times, two things are evident: They have no initial velocity and they accelerate as fast or slow as you would any object to accelerate under Earth gravity. The other thing is we aren't actually explicitly shown how high they were teleported. You would think not very high since they seemed to hit very soon after starting to fall, but if you ask yourself in how many shounen anime you have seen a person just stare at the opponent's surprising attack from the beginning till the end instead of trying to avoid it or anything else sensible, you would probably come to the conclusion they could have been 10 meters high as well. If they are made of tungsten alloy or depleted uranium, they would gain sufficient kinetic energy from several meters to produce the kind of impacts we saw.