Motion - zero velocity but still having acceleration

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Discussion Overview

The discussion centers around the concept of motion, specifically exploring examples of bodies that exhibit zero velocity while still experiencing acceleration. Participants seek to identify instances beyond the commonly cited example of a projectile at its peak height, where acceleration due to gravity is present despite the absence of velocity.

Discussion Character

  • Exploratory, Conceptual clarification

Main Points Raised

  • One participant asks for examples of bodies with zero velocity but non-zero acceleration, referencing the case of a body projected vertically upwards at its highest point.
  • Another participant suggests that reversing the direction of motion could be an example, though this is not elaborated upon.
  • A participant notes that there is always a frame of reference in which a body can have zero velocity, implying that context matters in defining motion.
  • One participant proposes a pendulum at the extremes of its swing as an example of zero velocity with acceleration.
  • Another participant mentions a ball thrown upwards, highlighting that at its highest point, the velocity is zero while the acceleration remains at -9.8 m/s².
  • A later reply introduces the scenario of a bungee jumper reaching the lowest point of their jump, where they also have zero velocity but experience acceleration.

Areas of Agreement / Disagreement

Participants present multiple examples and perspectives, indicating that there is no consensus on a singular example, but rather a collection of scenarios that illustrate the concept.

Contextual Notes

Some examples rely on specific conditions, such as the frame of reference or the nature of the motion (e.g., vertical motion, pendulum motion), which may not be universally applicable without further clarification.

Who May Find This Useful

This discussion may be of interest to students and enthusiasts of physics, particularly those exploring concepts of motion and acceleration in various contexts.

Kartik.
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Motion -- zero velocity but still having acceleration

What would be a example of a body having zero velocity but still having acceleration, except the example of a body projected vertically upwards and at the highest point it has no velocity but an acceleration equals 'g'?
 
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Reversing the direction something is moving in?
 


Kartik. said:
What would be a example of a body having zero velocity but still having acceleration,
There is always a frame of reference where a body has zero velocity.
 


Kartik. said:
What would be a example of a body having zero velocity but still having acceleration, except the example of a body projected vertically upwards and at the highest point it has no velocity but an acceleration equals 'g'?

An obvious one comes to mind: consider a pendulum at each end of its motion.
 


Or throw a ball upward. At its highest point the ball's velocity is 0 but its acceleration is still -9.8 m/s^2.
 


...or someone bungee jumping when they reach the lowest point.
 

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