I-I don't have time to stop it.

Felt pretty heroic at first, but...

- now I regret jumping in the van. - Ugh!

We're in the middle of a business district.

There really isn't a least-populated area.

Mac, how much room do you need for the blast?

Uh, okay, I'm looking at, uh,

a pound and a half of NP10.

Let's say two pounds to be safe, so...

pressure wave velocity of 1,030 feet per second.

Yeah, I don't understand a word you're saying,

so you just let me know when to turn, okay?

At the current external temperature,

I'd say air density is...

approximately 1.27 kilograms per meter cubed...

Yeah, uh, Mac, I don't want to interrupt,

but there's an alleyway coming up here on the right.

Factor the shockwave into the Hopkinson-Cranz Scaling Law

and the minimum safe distance becomes...

Mac! Alley?!