A proton, moving with a velocity of vi, collides elastically with another proton that is initially at rest. Assuming that after the collision the speed of the initially moving proton is 2.20 times the speed of the proton initially at rest, find the following. (a) the speed of each proton after the collision in terms of vi initially moving proton initially at rest proton xvi xvi (b) the direction of the velocity vectors after the collision (assume that the initially moving proton scatters toward the positive y direction) initially moving proton initially at rest proton relative to the +x direction relative to the +x direction