Why is the final potential of spring (Usf) equal to zero in problem b?

[F1ght4h0n0uR]

I'm having promblem with b. I checked the solution, but I did'nt understand the logic.

Kf+Ugf+Usf = Ki+Ugi+Usi

Usf= 0, Ki=0, Ugf= 0

I understand the logic's why they are equal to 0.

I don't understand why final potential of spring (Usf) is equal to zero?

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Now, I got it. I read the problem in detail.

 

[Joseph Martinez]

The potential energy that is stored in a spring depends on how far something is compressing or stretching the spring. So in b, when the object is at the bottom of the incline, it is no longer in contact with the spring, meaning it cannot be compressing the spring. since it is not compressing the spring that means there is no energy stored in it.

 

[F1ght4h0n0uR]

The potential energy that is stored in a spring depends on how far something is compressing or stretching the spring. So in b, when the object is at the bottom of the incline, it is no longer in contact with the spring, meaning it cannot be compressing the spring. since it is not compressing the spring that means there is no energy stored in it.

Thank you so much, I see it after posting thread.