What is the work function of the experimental photo-missive material? graph titled maximum kinetic energy of ejected photo electron versus incoming frequency is shown. the y axis is labeled maximum kinetic energy and scales from negative 3 to positive 3 electron volts. the x axis is labeled frequency from 0 to 11 times 10 to the 14 hertz. a line connects the points 0, negative 2 and 2.5, negative 1 and 5, 0 and 8, 1 and 10, 2.
a. 0.50 ev
b.-2.9 ev
c.-1.2 ev d.-2.0 ev

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

A26 cm object is 18 cm in front of a plane mirror. a ray of light strikes the object and is reflected off the mirror at a 42-degree angle. what is the angle of reflection? degrees what type of image is formed? what is the size of the image? cm

Gas cloud 1 is likely to form a star. gas cloud 2 is not. based on this information, match the given conditions with each cloud