Okay, let's break this down. So, escape velocity for the moon is 2.38 km/s. Let's just say that, in order to highball this, these rocks are moving at ten times that speed, so 23.8 km/s.
Now, the density of the moon is at average, 3.34 gm/cubic centimeter. Let's say that the nukes Wu was talking about were Hiroshima nukes, so 63 terajoules. Let's say 63 petajoules. One newton is one joule per meter, but acceleration is in one moment, so let's just say it's joules.
So, it's 6.3 times ten to the sixteenth joules equals mass times 23,800
Mass equals 2.6471 times ten to the twelfth kilograms. Volume is mass over density, so we have 7.925 times ten to the eleventh cubic centimeters, so we get an object 792,532 cubic meters in volume, or a cube 890 meters a side (2919.95 feet). Launching such an object is a waste anyway.
Yeah. While regular nukes in a polar orbit can hit faster, harder, more accurately with the bonus of packing more into a small area, this lunatic thinks firing objects at escape velocity from the Moon to the Earth is a better system. What's funny is the moon rock would take just under a week to make it, so there's plenty of warning.