A continuous linear acceleration craft would accelerate to half of the ship and provide gravity so that the floor for the astronauts faces opposite the direction towards which the ship is being accelerated. So if the ship accelerates at 4.9 meters.sec-2,
Humans can learn to move around in an environment rotating at a few RPM without serious side effects. In a rotating spacecraft, the RPM level that the crew could tolerate would be maximized, while the required level of artificial gravity (still unknown)