Sarah attempts to do the popular physics trick of swinging a pail of water around in a vertical circle fast enough so the water doesn't spill out when the pail is upside down. if her arm is 0.417 meters long, what is the minimum speed with which she can swing the pail so the water does not spill out at the top of the path? (assume that you may neglect the length of the pail).

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

Within a pendulum, as potential energy decreases, energy increases. a. heat b. kinetic c. frictional d. gravitational

Explain the comparisons between nature and packingtown that appears on pages 81 and 82 answer