- #1
apchemstudent
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Please DON'T delete this thread. I want to make a point here...
I want other experts in physics to determine who’s wrong in this situation…
This was the problem taken from:
https://www.physicsforums.com/showthread.php?t=58831
“A 5 kg block is fastened to a vertical spring that has a spring constant of 1000 Newtons per meter. A 3 kg block rests on top of the 5 kg block. The blocks are pushed down and released so that they oscillate.
Determine the magnitude of the max acceleration that the blocks can attain and still remain in contact at all times.”
Dextercioby agrees that the answer should be 9.8 m/s^2.
(I know I did something wrong in the other posts, but I’ve fixed it up)
Us + Up = Us(o) + Up(o)
kx^2/2 + 0 = mg2(x-.078) + 0 <- ------ It’s 2 times (x-0.078) due to the oscillation and 0.078 is the equilibrium point.
500x^2 – 156.8 x + 12.2304 = 0
x = 0.168 or x = 0.1456, but it’s asking for max acceleration so x = 0.168
Fs = 1000*0.168 = 168
Fnet = Fs – Fg
= 168 – 8*9.8
= 89.6 N
Amax = 89.6/8 = 11.2 m/s^2
I am pretty sure this is the correct answer. Everyone other then Dextercioby, please check if my method is right or wrong and can you explain why it might be wrong or right... thnx
I want other experts in physics to determine who’s wrong in this situation…
This was the problem taken from:
https://www.physicsforums.com/showthread.php?t=58831
“A 5 kg block is fastened to a vertical spring that has a spring constant of 1000 Newtons per meter. A 3 kg block rests on top of the 5 kg block. The blocks are pushed down and released so that they oscillate.
Determine the magnitude of the max acceleration that the blocks can attain and still remain in contact at all times.”
Dextercioby agrees that the answer should be 9.8 m/s^2.
(I know I did something wrong in the other posts, but I’ve fixed it up)
Us + Up = Us(o) + Up(o)
kx^2/2 + 0 = mg2(x-.078) + 0 <- ------ It’s 2 times (x-0.078) due to the oscillation and 0.078 is the equilibrium point.
500x^2 – 156.8 x + 12.2304 = 0
x = 0.168 or x = 0.1456, but it’s asking for max acceleration so x = 0.168
Fs = 1000*0.168 = 168
Fnet = Fs – Fg
= 168 – 8*9.8
= 89.6 N
Amax = 89.6/8 = 11.2 m/s^2
I am pretty sure this is the correct answer. Everyone other then Dextercioby, please check if my method is right or wrong and can you explain why it might be wrong or right... thnx
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