Question 7 (1 paint) A ball that was thrown up in the air is falling back down. What would its acceleration be at the top of the flight? ( 1) 9.8 m/s' in magnitude ( 51 9.B m/s' [up! Question 8 (1 paint) Which of the following is not a "scalar" quantity? O Al speed O B) time O Q pasition ( D) distance O E) mass Question 9 (1 paint) In a triathlon, participants swim for 750 m. bike for 20.0 km, and run for 3.0 km. If the time taken to complete the entire course is 1.2 h, the average speed, expressed in the proper manner, is [Assume all distances are accurate to the number of digits given.} O 1) 2.0 x 10* km/h O 2) 19.79 km/h ( 3) 24 km/h ( 4) 20.0 km/h ( 5) 23.750 km/h