A trained eye in the dark for an extended period of time may pick up a light stimulus from a light source, at the lowest radiated power of 1,2*10* (- 17) W. Determine how many photons of light with a wavelength of 500nm fall on the retina of the eye every second

Ahypothetical metal has an orthorhombic unit cell for which the a, b, and c lattice parameters are 0.413 nm, 0.665 nm, and 0.876 nm, respectively. (a) if there are 8 atoms per unit cell and the atomic packing factor is 0.536, determine the atomic radius (in nm). (b) if the density is 3.99 g/cm3, calculate the metal's atomic weight (in g/mol).

The two metal spheres in the figure are connected by a metal wire with w switch in the middle. initially the switch is open. sphere 1, with the larger radius, i'd given a positive charge. sphere 2, with the smaller radius, is neutral. then the switch is closed. afterward, sphere 1 has charge q1, is at potential v1 and the electric field strength at its surface is e1. the values for sphere 2 are q2, v2, and e2. a. is v1 < ,> , or = to v2? explain. b. is q2 < , > , or = explain? c. is e1 < ,> ,or = to e2? explain?

Stephanie lives in california, and her cousin thomas lives in france. which coordinate system would be most useful if the two wanted to observe the same meteor shower and discuss their observations over online chat as they're making them? a. horizontal b. equatorial c. azimuth-altitude d. celestial or azimuth-altitude