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
Messages
1
Reaction score
0
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?
 
Physics news on Phys.org
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:
 

Thread 'Rolling without slipping on a curved surface'

Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
View full post »

Thread 'Struggling to understand the concept of this question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
View full post »

Similar threads

Solving for Initial Velocity & Max Height of Thrown Ball
Replies
9
Views
2K
Ball thrown up, find max height - Given one velocity in midflight
Replies
4
Views
5K
Solving The Flight of a Ball: Examining Velocity & Time
Replies
2
Views
1K
Height of a projectile at two points?
Replies
5
Views
1K
Angular Momentum of a Ball at Half Height
Replies
9
Views
4K
"Vomit Comet" SpaceCraft (0)-V & H at Max Height
Replies
11
Views
2K
Conservation of Energy - Max height WITH Air resistance
Replies
4
Views
4K
How to Apply Derivatives in Physics Problems?
Replies
9
Views
1K
Projectile Motion Soccer Ball Problem
Replies
22
Views
5K
Finding the time and maximum height at highest point
Replies
6
Views
2K

Hot Threads

Recent Insights

Back
Top