5 mile final!
1. The Cessna will take two and a half minutes at 120 kts to reach the threshold of RWY 29 and could slow down if he/she was asked.
2. There is no wake turbulence standard required, only runway separation
3. B737 cleared for take off will take about 30 secs to enter runway and 30-40 seconds to become airborne
4. There will be then be a minute and a half left before the Cessna reaches RWY 29
5. Almost enough to get a second B737 airborne provided there was an outbound track split with the one already airborne, a medium weight turbo-prop would also fit nicely in the gap no track split required.
6. Re: previous posts about departure instructions, these can be obtained in advance or introduce auto-release procedures. (That is, the TWR controller does not have to ask for departure instructions)