A 39.2-kg boy, riding a 2.67-kg skateboard at a velocity of +5.37 m/s across alevel sidewalk, jumps forward to leap over a wall. Just afterleaving contact with the board, the boy's velocity relative to the sidewalk is 5.52 m/s, 9.72° above the horizontal. Ignore anyfriction between the skateboard and the sidewalk. What is the skateboard's velocity relative to the sidewalk at this instant? Besure to include the correct algebraic sign with your answer.