Problem $18.$ A $0\mathrm{.}2$ kg rubber ball is dropped from the window of a building. It strikes the

sidewalk below at $30($m$)/($s$)$ and rebounds up at $20($m$)/($s$).$ The magnitude of the impulse due to the

collision with the sidewalk is:

A$10$N$*$s

B$6\mathrm{.}0$N$*$s

C$2\mathrm{.}0$N$*$s

D$19\mathrm{.}6$N$*$s

E$9\mathrm{.}8$N$*$s