Final answer:
An object launched horizontally with a velocity of -12 m/s will continue to move horizontally at a constant velocity. In the vertical direction, the object will experience a decrease in velocity as it rises and an increase in velocity as it falls back towards the ground.
Step-by-step explanation:
In projectile motion, an object is launched horizontally with a velocity of -12 m/s. The motion of the object can be analyzed by breaking it into two independent one-dimensional motions along the vertical and horizontal axes.
In the horizontal direction, the velocity remains constant throughout the motion. The object will continue to move horizontally with a constant velocity of -12 m/s.
In the vertical direction, the object will experience a constant downward acceleration due to gravity. The vertical velocity will decrease as the object rises until it reaches its highest point where the velocity is zero. As the object falls back towards the ground, the vertical velocity increases again in magnitude but in the opposite direction to the initial vertical velocity.