Final answer:
A marble thrown horizontally with a speed of 15 m/s will follow a parabolic trajectory. It will maintain a constant speed when leaving the table's edge and when hitting the floor.
Step-by-step explanation:
The marble thrown horizontally with a speed of 15 m/s will undergo a parabolic trajectory. This is because the horizontal velocity remains constant, but the vertical velocity due to gravity changes over time, causing the marble to follow a curved path.
The marble will spend a certain amount of time in the air before it lands, which can be calculated using the equations of motion. The speed of the marble when it leaves the table's edge will also remain constant, as there are no horizontal forces acting on it.
When the marble hits the floor, it will have a non-zero vertical velocity due to gravity, but its horizontal speed will still be 15 m/s.