Required force to stop a moving object.

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To determine the force exerted by a man to stop a 6kg object moving at 10m/s in 30 seconds, the equation F = m*v(0)/30 was used, resulting in a force of 2 N. The solution is generally correct but should include units for clarity. An alternative approach suggested is to apply the impulse-momentum theorem for a potentially simpler calculation. The discussion emphasizes the importance of proper unit usage in physics problems. Overall, the calculations align with the principles of motion and force.
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Homework Statement


A solid object of 6kg was moving at a constant speed of 10m/s towards a man who try to stop it.
If the man stopped the train in 30 seconds, find the force F that the man exerted on the object.


The Attempt at a Solution


The only force acting on the object is the man's force so : ma=-F, this means that : v(t)=v(0)-F t /m.
We know that v(30)=0, which means that : F= m*v(0)/30 = 2.

Is my solution correct ? (I don't have anyone to ask him so I'm asking you).
 
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aziiri said:

Homework Statement


A solid object of 6kg was moving at a constant speed of 10m/s towards a man who try to stop it.
If the man stopped the train in 30 seconds, find the force F that the man exerted on the object.

The Attempt at a Solution


The only force acting on the object is the man's force so : ma=-F, this means that : v(t)=v(0)-F t /m.
We know that v(30)=0, which means that : F= m*v(0)/30 = 2.

Is my solution correct ? (I don't have anyone to ask him so I'm asking you).

Seems fine, but put in units.
 
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An alternative (and easier) way of doing this is to use the impulse-momentum theorem.
 

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