Need some help on relativity questions please!

Oct 2017
2
0
I am having hard time grasping the ideas of modern physics. I guess, I am not prepared for this class. Can someone look over the questions I solved so far? Also, I need some help on questions 4 and 5 too.
I will be dropping off this class and take it next semester, if I didn't do these questions well.

http://imgur.com/gallery/AR1rG3J