A force stretches a wire by 2mm. A second wire of the same material and with the same area of cross-section and twice the length is also stretched by the same force. What will its stretch be?
The Attempt at a Solution
F, Y, and A are all equal
F =(YA/L1)*2 mm
1. I set them equal to each other to solve for ΔL
(YA/2L1)ΔL = (YA/L1)*2
2. I canceled out YA
ΔL/2L1 = 2/L1
3. I multiplied both sides by 2L1 to isolate ΔL
ΔL = 4 mm
Did I do this correctly? I'm unsure because I've received notes from a friend and they got a different answer for the same problem. Thanks in advance.