Cycle II AP Physics

John Dewey High School

Mr. Klimetz

Holiday Homework

Problems in Thermal Energy

Solve the following problems either in the spaces provided or on a separate sheet of paper. Remember to employ proper problem-solving techniques throughout. Show all work, including equations, substitutions and units. Remember to highlight your answers.

1.   A beaker resting on a hot plate contains 1.000 liter of boiling water. It is observed to contain 850. ml of water after 100. seconds of boiling. Calculate (A) the amount of heat energy added to the beaker and (B) the average rate at which heat energy was added to the beaker during the observation period.

2.    Exactly 500. g of an unknown solid at room temperature is placed in a beaker of 500. g of room temperature water. Heat energy is added to the beaker for exactly 240. seconds. The final temperature of the water is 80 degrees C higher than its initial temperature. If the specific heat of the unknown solid is 0.1 that of water and presuming no losses of heat to the outside calculate (A) the total heat energy gained by the water, (B) the total heat energy gained by the unknown solid, and (C) the rate at which heat energy was added to the system.