A circular tube of length L = 0.5 m is loaded in compression forces P (see figure). The outside and inside diameters are 30 mm and 25 mm, respectively. A strain gage is placed on the outside of the bar to measure normal strains in the longitudinal direction.
(a) If the measured strain is ? = 900 X 10- 6, what is the shortening δ of the bar?
(b) If the compressive stress in the bar is intended to be 60 MPa, what should be the load P?
