Instaneous power delivered by the force at any timet

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Homework Help Overview

The discussion revolves around the instantaneous power delivered by a force acting on a particle of mass, specifically exploring the relationship between force, mass, and time in the context of physics principles.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the formula for power and its relation to work and force. There are inquiries about how to incorporate time and mass into the power formula. Suggestions include considering definitions of velocity and applying Newton's Second Law.

Discussion Status

The discussion is active, with participants exploring various approaches to the problem. Some guidance has been offered regarding the definitions and relationships involved, but no consensus or resolution has been reached yet.

Contextual Notes

Participants are navigating the constraints of the problem, including the need to derive relationships without explicit solutions and the implications of forces acting in different contexts, such as in a vacuum versus a fluid.

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A force F acts on a particle of mass m. The particle starts from rest at t=0.
a) show that the instaneous power delivered by the force at any timet is (F^2/m)*t
Please give some directions how to solve it . Thank you
 
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Any idea where to start? (hint: what is the formula for power)
 
formula P=W/t or P=FV , and I don't know how to get t and and m involve in the formula
 
Think of the definition of velocity. [tex]v = a t[/tex]. And then use Newton's Seond Law for [tex]a[/tex].
 
Thank you very much, I got it, and I have another homework.
A raindrop (m=3.35*10^-5 kg) falls vertically at a constant speed under the influence of gravity and air resistance. after the drop has fallen 100m,
a)what is the work done by gravity?
b)the energy discipated by air resistance?
I got no clue for air resistance . Thank you
 
If the raindrop where in the vacuum, the falling speed will not be constant. But when we do the experiment in a fluid, then a viscosity force appears and makes the raindrop or something else reach a constant speed. This force is proportional to the speed, so you may use Newtonian physics...
 
is it called resistive force?
 

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