When the sun is directly overhead, the thermal energy incident upon the earth is about 1.4 x 106 ergs- cm-2-sec-1. the diameter of the sun is about 1.6x 1011cm, and the distance from the sun to the earth is about 1.3 x 1013cm. assuming the that the sun radiates like a black body, use the expression to estimate its surface temperature.

The place you get your hair cut has two nearly parallel mirrors 6.00 m apart. as you sit in the chair, your head is 2.00 m from the nearer mirror. looking toward this mirror, you first see your face and then, farther away, the back of your head. (the mirrors need to be slightly nonparallel for you to be able to see the back of your head, but you can treat them as parallel in this problem.) how far away does the back of your head appear to be?

Determine the maximum r-value of the polar equation r =3+3 cos 0

Estimate the schwarzschild radius (in kilometers) for a mini-black hole formed when a superadvanced civilization decides to punish you (unfairly) by squeezing you until you become so small that you disappear inside your own event horizon. (assume that the your weight is 50 kg)