Beat frequency problem. Your ear simultaneously hears waves from different sources, so it can hear beats from the two speakers. In principle, the easiest way to measure the sound waves is to put a detector between the two speakers; however, in the experiment no detector is used to measure the wave field. Instead the voltages applied to the speakers are added electronically by the oscilloscope to simulate the true sound waves.

Suppose one speaker is driven at 570 Hz and the other at 554 Hz.

a. What is the beat frequency in Hz?
b. The average frequency in Hz?

Under conditions for which the same room temperature is maintained by a heating or cooling system, it is not uncommon for a person to feel chilled in the winter but comfortable in the summer. provide a plausible explanation for this situation (with supporting calculations) by considering a room whose air temperature is maintained at 20â°c throughout the year, while the walls of the room are nominally at 27â°c and 14â°c in the summer and winter, respectively. the exposed surface of a person in the room may be assumed to be at a temperature of 32â°c throughout the year and to have an emissivity of 0.90. the coefficient associated with heat transfer by natural convection between the person and the room air is approximately 2 w/m2 â‹…â‹… k. what is the ratio of the thermal resistance due to convection to the thermal resistance due to radiation in the summer? what is the ratio of thermal resistances in the winter

9.98 kg of r-134a at 300 kpa fills a rigid container whose volume is 14 l. determine the temperature and total enthalpy in the container. the container is now heated until the pressure is 600 kpa. determine the temperature and total enthalpy when the heating is completed. use data from the steam tables.

Scientific models are based on current knowledge, which can limit their effectiveness when new discoveries are made.