The average speed of Joe's fastball correct SI unit is m/s.
Answer: C
Step-by-step explanation
According to the problem given, the baseball thrown by Joe reaches the catcher's glove within the blink of audience's eyes.
Generally, human beings tend to blink their eyes every second to some minutes.
So as the ball reaches the catcher's glove within blink of eye that means the motion of the ball starting from thrown by Joe and ending at catcher's glove is completed within seconds. So the speed of the ball is in seconds.
As the catcher will be positioned at some meter distance so the distance traveled will be in meter in SI unit.
So the rate of change of distance per unit second is termed as velocity.
Thus the average speed will be recorded in m/s unit.