Bill Is Riding a Flatbed Railroad Car Travelling Down the Tracks

Multiple Choice

Bill is riding a flatbed railroad car travelling down the tracks at 16 m/s.The instant he passes Ted on the side of the train tracks,he throws a water balloon at him at such an angle that the balloon travels perpendicular to the train's direction of motion and strikes Ted squarely in the face.If Bill threw the balloon relative to the train at a speed of 24 m/s,with what speed did the balloon hit his friend?

A) 8 m/s
B) 18 m/s
C) 24 m/s
D) 29 m/s