Question 2 of 7 0.0 1.0 Points A 1070W heating element is immersed in 1.00 liter (1000cm3) of fluid initially at 11C. The properties of the fluid: (p=1044 kg/mC=4387J/kg.K. If we assume that the container is perfectly insulated all of the heat goes into the fluid) and that the liquid does not boil, estimate the time required to raise the temperature of the fluid to 108C. (Recall that 1W=1/5) Time = X 425539 seconds Answer Key:415 Question 3 of 7 0.0 1.0 Points A bar has a length of 50.0mm when measured at 20C. If the material has a thermal expansion coefficient of 1.9x10-6 /K, what is the expected change in length of the bar measured at 158C? * 0.1311 um. (1um=10-3mm) Answer Key:0.262 Question 4 of 7 1.0 2.0 Points You may have noticed that bridge decks are often built with expansion joints that permit the deck to expand and contract with changes in temperature. A bridge deck is to be made from steel, a=13.3x10-6/K) and is expected to operate over a temperature range -(-30)C to 45C. If the ramps to the bridge are precisely 17.5 meters apart and do not move with changes in temperature, and the deck must be sized such that no axial stress is developed due to thermal expansion: a) The length of the bridge deck measured at 23C must be no longer than 17.5 m (calculate to three decimal places. i.e. the nearest mm) b) The sum of the gaps at each end of the bridge at (-30)C will be x 17517.4 mm Answer Key:17.5,17.5 Question 5 of 7 0.0 1.0 Points Satellites in space can experience large thermal gradients. Surfaces facing away from the sun experience the average temperature in space, approximately 3K (-270C). Measurements made on an orbiting satellite recorded a maximum temperature of 297K for surfaces facing toward the sun. Determine the thermal strain, eth experienced by a satellite component (a=1.1E-5 /K) as it orbits the earth. eth= X 2.179/K Answer Key:0