A cylinder of length l, has a constant magnetic field B inside it, which is perpendicular to the cylinder axis. An electron of charge -e and mass m enters the cylinder with velocity v along the cylinder axis. If the radius of the cylinder is r = mveB, which of the following ensures that the electron leaves the cylinder with a velocity along the cylinder axis?

Researchers determine that the biodiversity in a woodland region is declining. they identify two major threats to the region's biodiversity, a method to address each threat, and the expected outcome of each method. this information is shown in the table. a) reforestation would not benefit many species because most forest species live on the ground. b) reforestation would take the longest time to be effective because trees take several years to grow. c) biological augmentation would benefit only a few species because is is typically not very effective. d) biological augmentation would take less time to ve effective because it targets the majority of prey species.