Seleba has a fire in the fireplace to warm her 20°C apartment. She realizes that she has left the iron poker in the fire. How hot is the fire if the 0.60 m poker lengthens 0.30 cm? (αiron = 1.2 x 10-5°C-1)
Answers
1. Most bridges contain interlocking steel grates (a steel = 12 x 10 - 6 C° -1) that allow the bridge to expand and contract with the changes in temperature. The Golden Gate Bridge in San Francisco is about 1350 meters long.
(A) The seasonal temperature variation in San Francisco ranges from about 0°C to 30°C. How much will the bridge expand between these two extremes?
(B) What percent of the length of a subcompact automobile, 2.5 meters, does this gap represent?
2. Selena has a fire in her fireplace to warm her 20°C apartment. She realizes that she has accidentally left the iron poker (a iron = 12 x 10 - 6 C° -1) in the fire. How hot is the fire if the 0.60-meter poker lengthens 0.30 cm?
3. Just before midnight, when the air temperature of 10.0°C, Karl stops and fills the 0.0600 m³ gas tank in his car. At noon the next day, when the temperature has risen to 32°C, Karl finds a puddle of gasoline (b gas = 3 x 10 -4 C° -1) beneath his car.
(A) What do you think happened?
(B) How much gasoline spilled out of Karl's car? (assume that there was virtually no change in the volume of his tank)
4. As he rides the train to work on a - 4°C winter day, Mr. Trump notices that he can hear the click of the train going over the spaces between the rails. Six months later, on a 30°C summer day, the rails are pushed together and he hears no clicks. If the rails are 5 meters long when the temperature is 30°C, how large a gap is left between the seel rails (a steel= 12 x 10 - 6 C° -1) on the cold winter day?
5. A popular winter activity of many college students is "traying," or sliding down a snow-covered hill on a tray borrowed from the dining hall. If Joanne removes a 0.35 meter x 0.65 meter aluminum tray (a aluminum = 24 x 10 - 6 C° -1) from the 20°C dining hall to go traying outside in the brisk - 8°C winter air, how much will the tray shrink when it is taken outside?