A typical human eye is nearly spherical, and is usually about 2.5 cm in diameter. Suppose a person first looks at a coin that is 2.1 cm in diameter and located 31.0 cm from her eye. Then, she looks up at a friend who is 1.8 m tall and 3.75 m away. Find the magnitude of the approximate size of each image (coin ℎI, coin and friend ℎI, friend ) on her retina. (Hint: Just consider rays from the top and bottom of the object that pass through the center of the lens.)

Ms.hidalgo opens the door to her classroom. her classroom is 60 degrees and the air outside is 80. predict what will happen using your knowledge of how heat flows.

The atoms in a nickel crystal vibrate as harmonic oscillators with an angular frequency of 2.3 × 1013 rad/s. the mass of a nickel atom is 9.75 × 10-26 kg. what is the difference in energy between adjacent vibrational energy levels of nickel? (h = 6.626 × 10-34 j • s, , 1 ev = 1.60 × 10-19 j)

Aspecified volume of space contains an electric field for which the magnitude is given by e=e0cos(ωt). suppose that e0 = 20 v/m and ω = 1.0 × 107 s−1. part a what is the maximum displacement current through a 0.80 m2 cross-sectional area of this volume? express your answer with the appropriate units. idisp,max i d i s p , m a x = nothing nothing request answer part b how would this area have to be oriented relative to the electric field to get this maximum displacement current?