How many miles can an atom bomb go in an hour?

Answer 1

I'm supposing you mean "after explosion" and not the "how fast can the bomb itself travel in air."

The WWII atom bombs (called "Little Boy" and "Fat Man") yielded about 60 terajoules (4E12 Joules) with a casing weight of nearly 4500 lbs and about 700 mg of explosive matter. Using work-energy relation, you get about 1.3E7 m/s = 13,000 km/s in the first few milliseconds. After about 2.5 seconds from detonation, on the order of 5000 m/s = 5 km/s.

Thus, in one hour (=3600 s), about 211,000 m = 211 km (a bit further than the distance between Philadelphia PA and New York City NY).