Four objects are released from the top of a hill of height H and roll to the bottom: a hoop, a hollow sphere, a solid sphere, and a solid cylinder
Each object has a mass M and a radius R.
Which of the following gives the order in which they reach the bottom of the hill, from first to last?

What is the frequency of a light wave with a wavelength of 620nm

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

Adiagram show how a converging lens can produce a real image and virtual image