Firmly hold with one hand the end of a ruler (or similar object) over the edge of a table. Pull the other end down gently and listen to the sound. Then give the ruler (or similar object) a harder downward pull, and see if there is a difference in sound. Describe what you hear and explain the difference using the terms “energy,” “amplitude,” “intensity,” and “decibel.” 2. Take some time to listen to sounds in your environment. Make a list of ten sounds, ranking them from the highest pitch to the lowest. Write a couple of sentences describing whether this was easy or difficult and why. (Some of the sounds can come from tapping objects that vibrate or playing musical notes on an instrument.)

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

Avector a⃗ has a length of 8.6 m and points in the negative x direction. find the x component of the vector −3.7a⃗ .

The path of a satellite orbiting the earth causes it to pass directly over two tracking stations a and b, which are 51 miles apart. when the satellite is on one side of the two stations, the angles of elevation at a and b are measured to be 87 degrees and 84 degrees, respectively. (a) how far is the satellite from station a? (b) how high is the satellite above the ground?