How Does Impulse-Momentum Theorem Determine Speed and Average Force?

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The discussion focuses on applying the impulse-momentum theorem to determine the speed of a 10 kg object at t=4 seconds and the average force acting on it from t=0 to t=4 seconds. The force function is provided, and the initial speed at t=0 seconds is given. The impulse-momentum theorem relates impulse to the change in momentum, indicating that impulse equals the total change in momentum over the specified time interval. Participants emphasize the need to understand the theorem's application, as examples are scarce in textbooks and online resources. The conversation highlights the importance of grasping this concept for solving the posed problems effectively.
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The force acting on a object ( 10 kg ) as function of time is given by :

F (t) = [ (-20t + 90)i - 60j + ( 10t + 40)k ] Newton

At time t=0 seconds , the speed of the object is given by :

V = [-14i + 26j + 32k ] m/s

question a )

use the impulse-momentum theorem for deciding the objects speed at t=4 ?

question B )

What is the average force acting on the object in the time interval t=0 -> t=4 ?



I can probably solve this task , but when I must use the theorem , I kind of get stuck

No examples of the use of this have I found online , not in textbook either
 
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kennien said:
use the impulse-momentum theorem for deciding the objects speed at t=4 ?

Hi kennien! Welcome to PF! :smile:

The impulse-momentum theorem is the impulse version of Newton's second law, F = d(mv)/dt.

Instead of force = rate of change of momentum (the ordinary version), the impulse version is impulse = total change of momentum (I = m∆v). :wink:
 
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