u/Chemical-Deer3334

In 1 question why did we take pie r^2 why not 4 pie r^2 if we assumed tht we count only area tht is normal to sun rays then ok buttttt,

In next ques 30 we took 4 pie r^2 for radiation wala sphere but why we took here 4 pie R^2 we took 4pie thts why we get r^2 and R^2 on numerator and denominator but here in this question they said tht consider area normal to rays

Why is like tht(⁠ノ⁠｀⁠Д⁠´⁠)⁠ノ⁠彡⁠┻⁠━⁠┻

1.Can't we cut dt there😅

2.Like I have marked there ,where did w came and also the negative sign

3. On the top why did we ignored the negative sign on Ldi by dt expression

The last one is my first one Mindmaps if anyone has any suggestions drop them