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.
Based on wind resistance, for example, the terminal velocity of a skydiver in a belly-to-earth (i.e., face down) free-fall position is about 195 km/h (122 mph or 54 m/s). This velocity is the asymptotic limiting value of the acceleration process, because the effective forces on the body balance each other more and more closely as the terminal velocity is approached.