Question

Jack D. Ripper throws a 4 gram pencil which lodges into a Sponge Bob doll that weighs 221 grams on its own. The doll was at rest on a rainbow with a coefficient of friction between itself and the doll of .325. The doll/pencil combination then slide 11.9 cm across the rainbow before coming to a stop. Determine the speed at which the pencil is moving prior to hitting the doll.