ElectricPavlov

I think, as the question is written......you're answers are correct.....AND you are correct again when you say the Q is confusing !   

I see now.....they start at the high point when theta = 0  originally     so they will be at 25 above center and never reach 15cm above that!      d'Oh!

NOW I am more confused     h = 25 cos(5theta)  is it's position from its CENTER......

 Is that what you assumed , Chris??

Disregard all of this......time to rethink my answers !!!!!

A   5 times every rotation is every 72 degrees

   10.62 + 72 =   82.62        154.62     226.62    298.62   370.62

   BUT, they also will be displaced 15 cm on the way DOWN for another 5 times each rotation

     arcos(-15/25) = 5t = .44 R    25.37 degrees  97.37   169.37  2.41.37  313.37  degrees

(I think !)

Ooops sorry....I gave onlt the FIRST position of those displacements.....back in a few

A:   15cm = 25cos(5t)      t= theta

     15/25 = cos 5t

     Arcos (15/25) = 5t      t= .185 R =10.62 degrees

B  -20 = 25 cos(5t)

    -20/25 = cos 5t

  Arcos (-20/25) = 5t    t = .4996 R   28.62 degrees

C   360 degrees/ (24 degrees/sec)  = 15 seconds

It is easy for me to see that .325 is greater....but here is another way to look at it....multiply BOTH numbers by 1000

to get   267    and    325       NOW  can you see the greater??

( I think you are calculating the DIFFERENCE in the  distance that you have fallen in those two different seconds)

If you use    d= 4.9+ 9.8 (t-1)   as the distance you fall EACH second  you will have to ADD the distance fallen each second to get the total meters fallen:

    4.9 + 9.8(8-1) +                         (73.5)

    4.9  + 9.8(9-1) +                         (83.3)

    4.9 + 9.8(10-1)  +                        (93.1)

    4.9 + 9.8 (11-1) +                        (102.9)

    4.9 + 9.8(12-1) +                          (112.7)

       TOTAL =   =============>  465.5     m    as before      Yah?