Strain, stress and elongation of the cable?

A steel cable 2.0 m long has a cross section area of .30cm^2. A 550 kg milling machine is now hung from the cable. Determine the stress, the strain, and the elongation of the cable. Assume that the cable behaves like a solid rod with the same cross section.

Strain, stress and elongation of the cable?getting late

1) the stress is the tensoin force over cross sectional area:

(550 kg (9.8 m/s^2))/.00003 m^2 = 1.8 * 10^8 N/m^2 or

180 mpa

2) to get strain we need to know youngs modulus for that material, that is delta stress over delta strain, or the slope of the stress/strain curve. it quantifies stiffness. it has the same units as stress.

strain is a length over a length, so it has no units. it is change in length over origional length, and can be calculated by:

strain = stress/youngs modulus (e) for that material.

(e = about 200 gpa for most steel)

3)elongation is the strain times the length.