Una nave espacial avanza en el espacio libre con una aceleracion constante de 9.0 m/s2. Si parte del reposo diga: ¿Que tiempo tardara en adquirir una rapidez igual a la decima parte de la rapidez de la luz ( c = 3.0 x 108 m/s)?

think its the third option

the moving of the box is a result of centripetal force. think of that  as a car or a truck in this case creates a turn, the force of friction performing upon the turned wheels of the car runs centripetal force obligatory for circular motion for the things inside it.