0.4kg ball is thrown straight up into the air and reaches a maximum altitude of 20m. Taking its initia position as the point of zero potentia energy and using energy methods, find (a) its initia] speed, (b) its total mechanical energy, and (c) the ratio of its kinetic energy to the potential energy when the ball is at an altitude of 10m.

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