A0.100-ma electron beam with kinetic energy 54.0 ev enters a sharply defined region of lower potential where the kinetic energy of the electrons is increased by 10.0 ev. what current is reflected at the boundary? (this simulates electron scattering at normal incidence from a metal surface, as in the davisson–germer experiment.)

Astone is thrown with a speed v0 and returns to earth, as the drawing shows. ignore friction and air resistance, and consider the initial and final locations of the stone. which one of the following correctly describes the change δpe in the gravitational potential energy and the change δke in the kinetic energy of the stone as it moves from its initial to its final location? options a.δpe = 0 j and δke = 0 j b.δpe is positive and δke is negative c.δpe = 0 j and δke is positive d.δpe is negative and δke is positive e.δpe = 0 j and δke is negative