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

[ProRip]

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?

 

[tiny-tim]

Welcome to PF!

Hi ProRip ! Welcome to PF!

"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!