Aluminum bar, 10 cm in diameter, 1 m long, 1 mm thickness Modulus of Elasticity = 70 GPa – Yield Stress = 280 MPa Coefficient of Thermal Expansion = 25 µm/m°C The bar is perfectly clamped at is outer edges, preventing any deformation. The initial temperature is 20°C. What is the stress in the bar if (is it tension or compression?):  Cooled to 0°C  Reheated to 20°C  Further heated to 100°C  Cooled to 20°C  Further cooled to ‐200°C  Reheated to 20°C