# Velocity vector and Max Height

#### 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

Homework Helper
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!

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