(a) If a rod of 1025 steel 0.5 m (19.7 in.) long is heated from 20°C to 80°C (68°F to 176°F) while its ends are maintained rigid, determine the type and magnitude of stress that develops. Assume that at 20°C the rod is stress-free. Assume positive stress for tension and negative for compression. (b) What will be the stress if a rod 1 m (39.4 in.) long is used? (c) If the rod in part (a) is cooled from 20°C to −10°C (68°F to 14°F), what type and magnitude of stress will result? Put positive stress for tension and negative for compression.