How to Calculate Power in a Physics Problem?

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Homework Help Overview

The discussion revolves around calculating power in a physics problem involving a force acting on a crate. The original poster presents a scenario where a 50-N force is applied to a 2-kg crate starting from rest, and they attempt to calculate the power after 2 seconds of force application.

Discussion Character

  • Exploratory, Mathematical reasoning

Approaches and Questions Raised

  • The original poster uses equations of motion and power calculations, questioning the accuracy of their distance calculation. Other participants discuss the distinction between average power and instantaneous power, suggesting different interpretations of the results.

Discussion Status

Participants are actively engaging with the calculations presented, with some confirming the original poster's approach while others provide alternative viewpoints on the power calculation. There is a mix of agreement and exploration of different aspects of the problem.

Contextual Notes

There is a mention of a multiple-choice list that the original poster's calculated power does not match, indicating potential constraints or expectations in the problem setup.

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Homework Statement



A 50-N force acts on a 2-kg crate that starts from rest. When the force has been acting for 2 s the rate at which it is doing work is:



Homework Equations


I used F = ma, d= Vit+1/2at^2, w=F*d, Power = W/t,


The Attempt at a Solution


F=ma, 50=2*a, a=25
d= 0*2+1/2(25)(2)^2
d=50
W = 50*50 = 2500
P = 2500/2 = 1250 and that's not on the multiple choice list.. I'm guessing I found the wrong distance?
 
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this u have calculated is average power in 2 sec .instantaneous is F.v
i think its 2500...

do tell me if i am correct
 
You're right!
You got V from kinematics right?
I did Vf = vi+at
so Vf = 0+(25)*2
and then 50*50=2500 ?
 
yeah
 

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