A lintel of prestressed reinforced concrete is 1.50 m long. The cross-sectional area of the concrete is 50.0 cm2. The concrete encloses one steel reinforcing rod with cross-sectional area 1.50 cm2. The rod joins two strong end plates. Young’s modulus for the concrete is 30.0 X 109 N/m2. After the concrete cures and the original tension T1 in the rod is released, the concrete is to be under compressive stress 8.00 X 106 N/m2.
(a) By what distance will the rod compress the concrete when the original tension in the rod is released?
(b) The rod will still be under what tension T2?
(c) The rod will then be how much longer than its unstressed length?
(d) When the concrete was poured, the rod should have been stretched by what extension distance from its unstressed length?
(e) Find the required original tension T1 in the rod.