A ball is thrown upward from the ground with an initial speed of 25m/s. At the same instant, another ball is
dropped from a hot air balloon that is rising a 5 m/s
and is 15m high. After how long with the balls be at the
same height? At what height do the paths of the balls.
cross? Does the first ball ever cross paths with the
balloon? If so, when and where?

It may seem strange that the selected velocity does not depend on either the mass or the charge of the particle. (for example, would the velocity of a neutral particle be selected by passage through this device? ) the explanation of this is that the mass and the charge control the resolution of the device--particles with the wrong velocity will be accelerated away from the straight line and will not pass through the exit slit. if the acceleration depends strongly on the velocity, then particles with just slightly wrong velocities will feel a substantial transverse acceleration and will not exit the selector. because the acc