An aluminum beam 80 m long and with a cross-sectional area of is used as part of a bridg...

An aluminum beam 80 m long and with a cross-sectional area of is used as part of a bridge. The beam is clamped rigidly at both ends. (a) If the temperature of the beam is increased by 30°C, what is the extra force exerted by the beam on one of its supports? (b) What is the force if the temperature of the beam is decreased by 40°C?