1 Harry is now totally panicked about the second task, since neither he nor Hermione can figure out how Harry can breathe underwater. 2  The night before the task, Fred and George show up with a message from Professor Dumbledore for Hermione and Ron. The night before the task, Fred and George show up with a message from Professor Dumbledore for Hermione and Ron. 2  Professor Dumbledore needs them for something. 3  Harry just keeps reading and reading, hoping  next book ... in the next one ... the next one  (26.72). 4  Finally, he nods off without realizing it.
The net force on the object then, is zero, and the result is that the velocity of the object remains constant. Terminal velocity is the highest velocity attainable by an object as it falls through a fluid (air is the most common example, but the concept applies equally to any fluid). It occurs when the sum of the drag force (Fd) and the buoyancy is equal to the downward force of gravity (FG) acting on the object.
As you can see, the terminal velocity of a body depends on many factors, like the mass of the body, density of the fluid, density of the body, gravitational acceleration, projected area of the body etc., and is not constant for a particular type of object. I hope that helps.