12. Projectiles move with a constant velocitijlr in. . . a. The horizontal rutdirection b. The vertical vdirection c. Both the x and vdirection d. In neither direction 13. Projectiles. move with an acceleration in. . . a. The horizontal rutdirection b. The vertical vdirection c. Both the x and vdirection d. In neither direction 14. In which direction do projectiles experience a net force? a. The horizontal xdirection b. The vertical vdirection c. Both the x and vdirection d. In neither direction 15. In an environment with air resistance, which ofthe following variables has the least effect on the path of a projectile? a. Gravitv b. The surface area and shape of the object c. Air resistance d. Mass