Acar that experiences no frictional force is started and caused to move. for the car to continue in that motion, the gas pedal would have to be used: at all times infrequently intermittently not at all a spacecraft is traveling in space far from any planets or stars. how much force is required to maintain the spacecraft's speed? 1/2 the mass of the spacecraft 1/4 the mass of the spacecraft none twice the mass of the spacecraft