A runner taking part in the 200 m dash must run around the end of a track that has a circular arc with a radius of curvature of 40 m. If he completes the 200 m dash in 23.8 s and runs at constant speed throughout the race, what is the magnitude of his centripetal acceleration (in m/sz) as he runs the curved portion of the track? A father fashions a swing for his children out of a long rope that he fastens to the limb of a tall tree. As one of the children swings from this rope that is 6.60 m long, his tangential speed at the bottom of the swing is 9.10 m/s. 1. a: . \"a \