Mechanical energy of a mass-spring system

AI Thread Summary
The discussion focuses on calculating the mechanical energy of a mass-spring system with given parameters: an amplitude of 0.026 m, a spring constant of 290 N/m, and a mass of 0.50 kg. The user is confused about how to incorporate acceleration into the energy calculations, specifically the relationship between potential energy (PE) and kinetic energy (KE). It is clarified that the mechanical energy can be calculated using the formula E = 0.5mv^2 + 0.5kx^2, and the user is advised to choose a specific point in the oscillation to simplify the calculations. The user expresses frustration over understanding the concepts of maximum displacement and velocity, particularly in relation to the maximum acceleration of 15.08 m/s. Ultimately, the user seeks clarity on how to derive the correct values for energy in Joules.
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Hey,
Stuck on finding the mechanical energy of a mass-spring system, my question is as follows > A mass-spring system oscillates with an amplitude of .026 m. The spring constant is 290 N/m and the mass is 0.50 kg, it asks for the mechanical energy in (J). and the maximum acceleration of the mass-spring system which is 15.08 m/s (verified, webassign rules).

Mechanical energy is confusing to me, I am pretty determined it might be potential(PE)enery + kinetic energy(KE), but ofcourse the formula for KE involves velocity. I only have the acceleration so I feel I have gone astray along the way.

Basically I am having trouble finding where to start and then I'm wondering how to get the answer in Joules.

Thanks.
 
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The mechanical energy of a mass-spring system with speed v at position x is E = .5mv^2 + .5kx^2 .

Pick a point in the oscillation and apply this equation. (Hint: there's a special point in its motion which simplifies this problem greatly).
 
Skomatth said:
The mechanical energy of a mass-spring system with speed v at position x is E = .5mv^2 + .5kx^2 .

Pick a point in the oscillation and apply this equation. (Hint: there's a special point in its motion which simplifies this problem greatly).

Thanks for the reply. I assume when you say pick a point you mean pick a point to plug in for the variable V. The amplitude is .026m

So far I have this

E=.25v^2 + 0.09802

Would V be 1/2 of the maximum acceleration?
 
When the mass it as its maximum displacement what is its velocity? You should know this without having to use a formula. If you don't, review the chapter.
 
Last edited:
Skomatth said:
When the mass it as its maximum displacement what is its velocity? You should know this without having to use a formula. If you don't, review the chapter.

:bugeye: The chapter has been read very carefully by me twice. We haven't really covered mass at its maximum displacement, or maybe we have and called it something else.

I think by maximum displacement you mean the amplitude which is ofcourse .026m. Maximum accel. is 15.08 m/s . I realize the answer is probably smack in front of me but with only one submission left on web assign I remain wary. I still am a bit confused at how to find the velocity with mass, amplitude, max. accel, and 290N/M.
 
Wow I am stupid!
KE= 1/2 290 N/m * (.026)^2

Thanks!
 
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