#### Kryptid

##### ACCESS: Secret

- Joined
- 12 March 2009

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Does this seem wrong to anyone else?

Here is the math in case anyone wants to check over it:

Here are the calculations to find the volume of the Sears-Haack body:

Volume = ((3 x pi^2)/16) x maximum radius^2 x length

Volume = ((3 x pi^2)/16) x 1.76 feet^2 x 49.2 feet

Volume = 282 cubic feet

These are the calculations to find the drag force at Mach 1 at 36,000 feet (660 miles per hour/968 feet per second)

Wave drag = ((64 x Volume^2)/(pi x Length^4)) x air density x velocity^2

Wave drag = ((64 x 282 cubic feet^2)/(pi x 49.2 feet^4)) x 0.00072 slugs/cubic feet x 968 feet per second^2

Wave drag = 186.5 pounds

I saw in Raymer's design book that slugs per cubic foot are the go-to measurement for air density when using imperial units. Should I have used pounds per cubic foot instead?