Finding the change in velocity from an acceleration vs time graph

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SUMMARY

The discussion focuses on calculating the change in velocity from an acceleration vs time graph, specifically over the interval from 0 to 4 seconds. The correct change in velocity is determined to be 8 m/s, despite initial confusion regarding the relationship between decreasing acceleration and increasing velocity. The key takeaway is that positive acceleration indicates an increase in velocity, even if the rate of that increase is diminishing over time.

PREREQUISITES
  • Understanding of kinematics, specifically the relationship between acceleration and velocity.
  • Familiarity with interpreting acceleration vs time graphs.
  • Knowledge of calculus concepts related to area under a curve.
  • Basic proficiency in physics equations, particularly a = v/t.
NEXT STEPS
  • Study the concept of area under the curve in relation to acceleration vs time graphs.
  • Learn about the implications of positive and negative acceleration on velocity changes.
  • Explore kinematic equations and their applications in motion analysis.
  • Investigate real-world examples of varying acceleration and its effects on velocity.
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Students studying physics, educators teaching kinematics, and anyone interested in understanding the dynamics of motion and acceleration.

MattDutra123
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Homework Statement


The graph shows the variation with time t of the acceleration a of an object (graph attached).
What is the change in velocity of the object in the time interval 0 to 4s?

Homework Equations


a = v/t

The Attempt at a Solution


My initial answer was -8 m/s, by simply finding the area under the curve. However, the correct answer is 8 m/s (positive). I don't understand how acceleration could be decreasing if the velocity isn't. How can acceleration decrease when the velocity is increasing?
 

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MattDutra123 said:

Homework Statement


The graph shows the variation with time t of the acceleration a of an object (graph attached).
What is the change in velocity of the object in the time interval 0 to 4s?

Homework Equations


a = v/t

The Attempt at a Solution


My initial answer was -8 m/s, by simply finding the area under the curve. However, the correct answer is 8 m/s (positive). I don't understand how acceleration could be decreasing if the velocity isn't. How can acceleration decrease when the velocity is increasing?

Acceleration = rate of change of velocity, so as long as acceleration is positive, the velocity is increasing. In this case, the rate at which velocity increases becomes less as time passes, but it is still positive.
 
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