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
Both Alex and his friend observe it as less than 10 meters per second .
B
Alex observes it as 10 meters per second , and his friend observes it as less than 10 meters per second .
C
Alex observes it as less than 10 meters per second , and his friend observes it as 10 meters per second .
D
Both Alex and his friend observe it as 10 meters per second .
Explanation
Alex and his friend are both standing still, so they share the same reference frame. The football’s speed relative to each of them is 10 meters per second while it is in flight. The 5-meter distance affects how long it takes the ball to reach the friend, not the speed either person observes.
AI-written and checked against the verified answer.