7. How many moles of gas are in a bike tire with a volume of 2.00x10-3 m', a pressure of 7.00x105 Pa and at a temperature of 18.09C? 8. (a) What is the average kinetic energy of a gas molecule at 20.09C (room temperature)? (b) Find the rms speed of a nitrogen molecule (N2) at this temperature.. 9. The vapor pressure of water at 20.09C as 2.33x10 Pa. Use the ideal gas law to calculate the density of water vapor in g/m' that would create a partial pressure equal to this vapor pressure. Compare the result with the saturation vapor density. 10. Calculate the wavelengths of sounds at the extremes of the audible range, 20 and 20,000 Hz, in 30.09C air. 11. Calculate the sound intensity level in decibels for a sound wave traveling in air at 0 C and having a pressure amplitude of 0.656 Pa. 12. Show that if one sound is twice as intense as another, it has a sound level about 3 dB higher.13. Find the Length of a Tube with a 128 Hz Fundamental (a) What length should a tube closed at one end have on a day when the air temperature, is 22.09C, if its fundamental frequency is to be 128 Hz (C below middle C)? (b) What is the frequency of its fourth overtone? 14. A 0.500 kg aluminum pan on a stove is used to heat 0.250 liters of water from 20.09C to 80.09C. (a) How much heat is required? What percentage of the heat is used to raise the temperature of (b) the pan and (c) the water? 15. Calculate the temperature increase of 100 kg of brake material with an average specific heat of 800 J(kg"C) if the material retains 10% of the energy from a 10,000-kg truck descending 75.0 m (in vertical displacement) at a constant speed. 16. Suppose you pour 0.250 kg of 20.0C water (about a cup) into a 0.500-kg aluminum pan off the stove with a temperature of 1509C. Assume that the pan is placed on an insulated pad and that a negligible amount of water boils off. What is the temperature when the water and pan reach thermal equilibrium a short time later? 17. A Styrofoam ice box has a total area of 0.95 m & walls with an average thickness of 2.5cm. The box contains ice, water, and canned beverages at 09C. The inside of box is kept cold by melting ice. How much ice melts in one day if the ice box is kept in the trunk of a car at 359C?Homework-4 Please solve all questions by due date to get the full credit 1. "Room temperature" is generally defined to be 259C. (a) What is room temperature in OF? (b) What is it in K? 2. The main span of San Francisco's Golden Gate Bridge is 1275 m long at its coldest. The bridge is exposed to temperatures ranging from -15.C to 40C. What is its change in length between these temperatures? Assume that the bridge is made entirely of steel. 3. Suppose your 60.0-L (15.9-gal) steel gasoline tank is full of gas, so both the tank and the gasoline have a temperature of 15.09C. How much gasoline has spilled by the time they warm to 35.09C? here Bgas - Bs =950 -35 4. Suppose your bicycle tire is fully inflated, with an absolute pressure of 7.00x10 Pa at a temperature of 18.09C. What is the pressure after its temperature has risen to 35.09C? Assume that there are no appreciable leaks or changes in volume. 5. Calculate the number of molecules in a cubic meter of gas at standard temperature and pressure (STP), which is defined to be OC and atmospheric pressure. 6. Calculate: (a) the number of moles in 1.00 m3 of gas at STP, and (b) the number of liters of gas per mole.16. Suppose you pour 0.250 kg of 20.0C water (about a cup) into a 0.500-kg aluminum pan off the stove with a temperature of 1509C. Assume that the pan is placed on an insulated pad and that a negligible amount of water boils off. What is the temperature when the water and pan reach thermal equilibrium a short time later? 17. A Styrofoam ice box has a total area of 0.95 m & walls with an average thickness of 2.5cm. The box contains ice, water, and canned beverages at 09C. The inside of box is kept cold by melting ice. How much ice melts in one day if the ice box is kept in the trunk of a car at 359C