Has the Ball Passed Its Highest Point Based on Velocity Vector?

AI Thread Summary
The discussion centers on whether a fly ball with a velocity vector of v->=25i-4.9j has passed its highest point. The book states that the ball has not yet reached its maximum height, while the user argues that the negative j component indicates the ball is falling, suggesting it has passed its peak. Participants confirm that the negative j component indeed means the ball is moving downward. This leads to the conclusion that the book's answer may be incorrect. The conversation highlights a misunderstanding of projectile motion dynamics.
ProRip
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This is a question from "Fundamentals of Physics 8th Edition Extended, Chapter 4, Checkpoint3."

"At a certain instant, a fly ball has velocity v->=25i-4.9j (the x-axis is horizontal, the y-axis is upward, and the v-> is in metres per second). Has the ball passed its highest point?

The answer in the book says it hasn't...?

But I believe it has as -4.9j means the ball is now falling towards the ground therefore it has past its max height within the projectile motion.

Am I incorrect, or is the book wrong??, If I'm incorrect can someone point out why?
 
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Welcome to PF!

Hi ProRip ! Welcome to PF! :smile:
ProRip said:
"At a certain instant, a fly ball has velocity v->=25i-4.9j (the x-axis is horizontal, the y-axis is upward, and the v-> is in metres per second). Has the ball passed its highest point?

The answer in the book says it hasn't...?

But I believe it has as -4.9j means the ball is now falling towards the ground therefore it has past its max height within the projectile motion.

Yup … minus j means it's moving downward …

looks as if the book is wrong! :redface:
 

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