Specimen of steel has a rectangular cross section 20 mm wide and 40 mm thick, an elastic modulus of 207 GPa, and a Poisson’s ratio of 0.30. If this specimen is pulled in tension with a force of 60,000 N, what is the change in width if deformation is totally elastic? (A) Increase in width of 3.62  10−6 m (B) Decrease in width of 7.24  10−6 m (C) Increase in width of 7.24  10−6 m (D) Decrease in width of 2.18  10−6 m

(D) Decrease in width of 2.18 x m

Explanation:

Given:

force 'F'= 60,000 N

elastic modulus 'E' = 207 GPa => 2.07 x  N/m²

cross section area ' '= 20 mm x 40 mm => 800mm² =>8 x m²

∈z = б/E => (F/ )/E => F/ E

∈z = 60,000/(8 x x 2.07 x  )

∈z =3.62 x  

Lateral strain is given by,

∈x= -v∈z => -(0.30)(3.62 x  )

∈x=1.09  x  

Next is to calculate the change in width

ΔW= Wo x ∈x =>20 x 1.09  x  

ΔW= -2.18 x   m

Therefore, the correct option is 'D'

i think it’s a. this is because if they measured the mass of something with a mass of 150g, then their final answer would have to be approximately 150g. though all of their answers are almost 150, rosa and tran have the closest answers (or the exact answer) to the accurate one.

sleep paralysis is a parasomnia, events associated with sleep.

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i had a friend that had sleep paralysis and he told me a story one time where he was laying in bed and he couldn't move his body no matter how hard he tried and there was someone standing in the corner of his room coming towards him. he couldn't move and you can't "wake up" because you are already conscious. sometimes sleep paralysis can be triggered by frequent waking up during the night based off of multiple trips to the bathroom, or if you had ever been abused, sleep paralysis can start happening from things like that.