Final answer:
A negatively charged massive particle dropped between two plates with an electric field will follow a rightward-curving parabolic trajectory. A horizontally launched ball will have a constant negative vertical acceleration due to gravity. The resulting motion is a downward-opening parabola for objects in projectile motion near the Earth's surface.
Step-by-step explanation:
When considering the trajectory of a negatively charged massive particle that is dropped into the space between two plates, we need to take into account the direction of the electric field between the plates. If we assume the electric field is directed from the positive to the negative plate, the negatively charged particle will be attracted towards the positive plate, resulting in a rightward-curving parabola due to the combined effects of the electric force and gravity.
In the case of a ball launched horizontally, the vertical acceleration due to gravity is constant and directed downwards, giving the acceleration versus time graph the shape of a horizontal line at the negative value of the acceleration due to gravity (-9.8 m/s2).
An example of a parabola created in projectile motion is when a ball or projectile is launched horizontally from an elevation. This parabola will open downward because the only acceleration acting on the projectile is the constant acceleration due to gravity.