In a television tube, electrons initially at rest are accelerated by a uniform electric field of magnitude 4.0 105 N/C during the first 5.0 cm of the tube's length; then they move at essentially constant velocity another 45 cm before hitting the screen. (a) Find the speed of the electrons when they hit the screen.

Question

In a television tube, electrons initially at rest are accelerated by a uniform electric field of magnitude 4.0  105 N/C during the first 5.0 cm of the tube's length; then they move at essentially constant velocity another 45 cm before hitting the screen. (a) Find the speed of the electrons when they hit the screen.

bobpursley · Answer

KE= Eq*distance KE= 1/2 mv^2, and v= sqrt 2KE/m solve for KE, then v.