An olympic runner completes the 200-meter sprint in 23 seconds. what is the runner’s average speed? (round your answer to the nearest tenth of a meter per second.) 0.9 m/s 1.2 m/s 8.7 m/s 10.1 m/s

Olympic skier tina maze skis down a steep slope that descends at an angle of 30∘ below the horizontal. the coefficient of sliding friction between her skis and the snow is 0.10. i found maze's acceleration which is 4.1 m/s^2. but how do you determine maze's speed 4.0 s after starting?