Word problems

I know that i should have posted this a long time ago, but this past month has been a killer for me. Well, it was a good test of time management and mental toughness though so without further ado, here's one of the comments i made a month ago:

After doing the whole question by myself, I must say that this is the most challenging question among the bunch. It took me about 35 minutes and a lot of coffee. I think that you have the arrow of the wave on the left of the x-axis on the right position contrary to what other people say. Good luck on the upcoming test.

-m@rk

Also, i made another comment on the same assignment from a different group:

Paul,

I think you made a good point. I also think that the amplitude should be 20 because the ferris wheel is 1 meter above the ground.That being said the vertical shift will change too,it will be 21. Like you said it is a matter of one's interpretation. Now, i kinda like to go to class once in a while to see the class's progress but too bad i still have my AP class.

-m@rk