Scientists are testing a new drug, which they think might allow people to memorize large amounts of information. group a is taking a sugar pill. group b is taking the new drug. both groups are 25–35 years old and are not taking any other medicine. after a month, both groups will be given a memorization test, and scientists will compare each group’s ability to memorize new information. which choice is the independent (manipulated) variable?

a.
the sugar pill

b.
the new drug

c.
the ability to retain short-term memories

d.
the test subjects

The equation that describes a transverse wave on a string is y = (0.0120 m)sin[(927 rad/s)t - (3.00 rad/m)x] where y is the displacement of a string particle and x is the position of the particle on the string. the wave is traveling in the +x direction. what is the speed v of the wave?

Protons and neutrons are found within the nucleus of an atom

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