Acceleration of a ball thrown upwards.

  • Thread starter Thread starter kbncp
  • Start date Start date
  • Tags Tags
    Acceleration Ball
Click For Summary

Homework Help Overview

The problem involves analyzing the acceleration of a ball thrown upwards at different points in its trajectory, specifically just after leaving the hand, at the highest point, and just before hitting the ground. The context is kinematics, focusing on the effects of gravity on the ball's motion.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants discuss the nature of acceleration at various points in the ball's flight, with some attempting to justify their answers based on the ball's motion and the effects of gravity. Questions arise regarding the distinction between speed and velocity, and the implications of neglecting air friction.

Discussion Status

The discussion is ongoing, with some participants questioning the correctness of the original poster's answers and encouraging deeper reasoning. There is a mix of interpretations regarding the relationship between velocity and acceleration, and the role of air resistance is also mentioned.

Contextual Notes

There is an assumption that air friction is neglected, which may affect the accuracy of the answers provided. The original poster's responses are noted as potentially incorrect, prompting further exploration of the concepts involved.

kbncp
Messages
4
Reaction score
0

Homework Statement


A ball is thrown up the top of the tower. At each of the following instants is the ball's acceleration larger than g, equal to g, or -g (assume up is positive, g=9.8m/s2)
a) Just after leaving your hand?
b) When the ball is at its highest point?
c) Just before hitting the ground?


Homework Equations





The Attempt at a Solution


a) -g
b) -g
c) g
 
Physics news on Phys.org
Your answers are not all correct: but you should say more about how you arrived at your answers. If they are random guesses then you should try harder.

In any case, I suppose air friction is neglected here, otherwise the correct answer is not always among the 3 choices!
 
well the first two answers.. since the ball is moving up.. it is eventually going to reach a velocity of 0, so it slows down.. so acceleration is -g... And when it is moving down... the velocity gets faster and faster.. so i would assume that the acceleration would be g
 
Maybe you're confusing speed and velocity: it's not just about "speeding up" or "slowing down," [which refer to speed, really] it's the direction of the change in velocity which is important.
 

Similar threads

Replies
24
Views
4K
Replies
5
Views
2K
Replies
12
Views
2K
Replies
34
Views
3K
Replies
26
Views
5K
  • · Replies 38 ·
2
Replies
38
Views
5K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 5 ·
Replies
5
Views
14K
Replies
7
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K