Physics Question

Question

A 210-kg load is hung on a wire of length of 3.50 m, cross-sectional area 2.00  10^-5 m², and Young's modulus 8.00  10¹⁰ N/m². What is its increase in length?

Answer: _____ mm

Answer 1

Use these equations:

Stress:

σ = F/A = mg / A

You were given m and A, and you know g. Plug in the numbers and get σ.

σ = εE = (ΔL / L)E ⇒

ΔL = σL / E

You were given the length L and Young's modulus E, and you calculated σ above. Plug in the numbers and get ΔL in meters, and then convert to mm.