Train car Ais at rest when it is hit by train car B. The two cars, which have the same mass, are stuck together and move off after the collision. How does the final velocity of train cars A and B after the collision compare to the initial
velocity of train car B before the collision?
O The final velocity is double train car B's initial velocity.
The final velocity is the same as train car B's initial velocity.
The final velocity is half of train car B's initial velocity.
The final velocity is zero since train car B will stop.

Consider each of the electric- and magnetic-field orientations given next. in each case, what is the direction of propagation of the wave? a)\vec ein the +xdirection,\vec bin the +ydirection. choose+ x direction- x direction+ y direction- y direction+ z direction- z direction b)\vec ein the -y direction,\vec bin the +x choose+ x direction- x direction+ y direction- y direction+ z direction- z direction c)\vec ein the +z direction,\vec bin the -x direction. choose+ x direction- x direction+ y direction- y direction+ z direction- z direction d)\vec ein the +y direction,\vec bin the -z direction. choose+ x direction- x direction+ y direction- y direction+ z direction- z direction