Re: Full impulse
Full impulse is 1/4 the speed of light.
That's not what it says in TMP. When the Enterprise is leaving drydock:
KIRK: Impulse power, Mister Sulu. Ahead, warp point five.
So they can go at least half the speed of light on impulse power.
One could also interpret it this way --- Kirk said Warp
.5 ^ 3 = .125c
"You have been examined. Your ship must be destroyed. We make assumption you have a deity, or deities, or some such beliefs which comfort you. We therefore grant you ten Earth time periods known as minutes to make preparations."