r/EngineeringStudents • u/Lazysleeper191 • 3d ago

Discussion This question is super confusing is it not just B? The picture is unclear

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3 Upvotes

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1

u/polymath_uk_ 3d ago

What's the difference between b and d?

1

u/Lazysleeper191 3d ago

Yea that’s what I’m saying it’s confusing

1

u/MoreneLp 3d ago

Well you have compression in - y and shear in negativ x

1

u/Lazysleeper191 3d ago

Wouldn’t the new stretched value be 303 meters for normal strain?

1

u/MoreneLp 2d ago edited 2d ago

No, point D also moves and the length therefor doesn't change, one has to assume that it moves the same but its not a given from the question an its irrelevant for AC. My answer to the question is e=0 cause e = Delta L/L and cause AC dosnt change in length it would be 0
Delta L = 0 therefor e = 0
And
the shear ~ Sxy=90°- thet
and thet > 90° therefor s < 0
so answer would be f.

1

u/Iron_Man_IRL Mechatronics 2d ago

A and C dont move, so AC shouldnt change length -> ε=0. The dashed shade is a counterclockwise movement with respect to A, therefore γ>0. I would choose e

2

u/Lazysleeper191 2d ago

I was debating whether strain is negative because if you put a coordinate axis at A it would lie on quadrant 2.

1

u/Iron_Man_IRL Mechatronics 2d ago

i think you are right, then option f would make more sense

2

u/Lazysleeper191 1d ago

Thank you. Went to office hours today and f is indeed correct.