Alex is standing still and throws a football with a speed of 10 meters per second to his friend, who is also standing still. The two friends are standing 5 meters apart. Which describes how each person observes the speed of the football?
Answer
A
Alex observes it as 10 meters per second , and his friend observes it as less than 10 meters per second .
B
Alex observes it as less than 10 meters per second , and his friend observes it as 10 meters per second .
C
Both Alex and his friend observe it as less than 10 meters per second .
D
Both Alex and his friend observe it as 10 meters per second .