1. A blacksmith heats a piece of iron until it glows bright yellow at a temperature...

 

 

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1. A blacksmith heats a piece of iron until it glows bright yellow at a temperature of 2200 F. What is its temperature in the Kelvin scale? 2. A cold front came and the temperature in Tampa drops from 70 F to 50F. What is the change in temperature in Celsius and in Kelvin? 3. *The helium gas in the outer layer of the sun has an average temperature of 9941 F. What is the average speed of a helium atom at this temperature? The mass of a helium atom is 6.6 x 10-27 kg. 4. *How much heat is required to melt 0.04 kg of ice at 0 C and then raise the temperature of the melted water to 30C? 5. An ice cube of mass 0.5 kg is initially at a temperature of -10 C. If the ice cube absorbs 15,000 joules of heat, what will be its final temperature? 6. *An ornamental pond is 0.8 m deep and has a surface area of 100 m. If the sunlight falling on the pond transfers energy to the surface of the pond at an average rate of 200 watts/m2, find the time it will take to raise the temperature of the pond from 41 F to 68 F. Assume that all of the heat absorbed by the water remains in the water. 7. A bricklayer drops lump of mortar from a point 30 meters up the side of a brick building he is working on and it hits the ground with a splat. Mortar has a specific heat of 1200 J/(kg K). By how many degrees will the mortar be warmer, assuming that all the energy it acquires during the drop is converted to internal energy inside the mortar and not the ground? 8. *A 2-kg block of copper is heated to 400 C and dropped into an insulated bucket that contains a mixture of ice and water at 0 C. The final temperature of the copper is 0 C. How much ice melted in the process? 9. *The total internal kinetic energy of 5 gallons of water is 2 x 108 J. The total internal kinetic energy of the water in a 100,000-gallon swimming pool is 5 x 10 J. (1 Gallon 0.003785 m. Density of the water = 1000 kg/m. The atomic mass of water is 18 u.) a. How many water molecules are in the 5-gallon water? b. Which body of water is at higher temperature? Explain your answer. 10. When a 100-gram cylinder of copper, initially at 100 C, is placed in 100 grams of household ammonia, originally at 20 C, the final temperature of the ammonia is measured to be 26 C. What is the specific heat of the household ammonia? 11. A metal cylinder is made of 50 g of silver and 120 g of copper. It is heated to 100 C and then placed in 400 grams of water at 10 C, which is contained in a well-insulated can of negligible mass. What will be the final temperature of the cylinder in the can of water? 12. A 10-gram ice cube at 0 C is dropped into 100 grams of water at 10 C. The water and ice cube are well insulated from the outside environment. Will the ice cube melt complete or not? Justify your answer. 1. A blacksmith heats a piece of iron until it glows bright yellow at a temperature of 2200 F. What is its temperature in the Kelvin scale? 2. A cold front came and the temperature in Tampa drops from 70 F to 50F. What is the change in temperature in Celsius and in Kelvin? 3. *The helium gas in the outer layer of the sun has an average temperature of 9941 F. What is the average speed of a helium atom at this temperature? The mass of a helium atom is 6.6 x 10-27 kg. 4. *How much heat is required to melt 0.04 kg of ice at 0 C and then raise the temperature of the melted water to 30C? 5. An ice cube of mass 0.5 kg is initially at a temperature of -10 C. If the ice cube absorbs 15,000 joules of heat, what will be its final temperature? 6. *An ornamental pond is 0.8 m deep and has a surface area of 100 m. If the sunlight falling on the pond transfers energy to the surface of the pond at an average rate of 200 watts/m2, find the time it will take to raise the temperature of the pond from 41 F to 68 F. Assume that all of the heat absorbed by the water remains in the water. 7. A bricklayer drops lump of mortar from a point 30 meters up the side of a brick building he is working on and it hits the ground with a splat. Mortar has a specific heat of 1200 J/(kg K). By how many degrees will the mortar be warmer, assuming that all the energy it acquires during the drop is converted to internal energy inside the mortar and not the ground? 8. *A 2-kg block of copper is heated to 400 C and dropped into an insulated bucket that contains a mixture of ice and water at 0 C. The final temperature of the copper is 0 C. How much ice melted in the process? 9. *The total internal kinetic energy of 5 gallons of water is 2 x 108 J. The total internal kinetic energy of the water in a 100,000-gallon swimming pool is 5 x 10 J. (1 Gallon 0.003785 m. Density of the water = 1000 kg/m. The atomic mass of water is 18 u.) a. How many water molecules are in the 5-gallon water? b. Which body of water is at higher temperature? Explain your answer. 10. When a 100-gram cylinder of copper, initially at 100 C, is placed in 100 grams of household ammonia, originally at 20 C, the final temperature of the ammonia is measured to be 26 C. What is the specific heat of the household ammonia? 11. A metal cylinder is made of 50 g of silver and 120 g of copper. It is heated to 100 C and then placed in 400 grams of water at 10 C, which is contained in a well-insulated can of negligible mass. What will be the final temperature of the cylinder in the can of water? 12. A 10-gram ice cube at 0 C is dropped into 100 grams of water at 10 C. The water and ice cube are well insulated from the outside environment. Will the ice cube melt complete or not? Justify your answer.