.
By changing the origin for the time, you may forget about and write the formula for SHM in the form
x = .
It is totally enough to solve the problem.
Now, when x= 5 cm, you have 5 = , or
= .
Next, the velocity is the DERIVATIVE of the position function x = x(t)
Velocity = () = .
You just know the cosine function from (1) - so you can calculate
= .
In this way, you can complete calculations for velocity.
Then for acceleration, use the fact that it is THE SECOND DERVATIVE of the position function and do the same.
At this point I completed my instructions.
Are they clear to you ?
If you still have difficulties/questions, let me know by posting your message through the "Thank you" window.
In this case, refer to the problems ID number, which is 1142816.
(otherwise, I will not to know to whom to answer).
Keep me informed about your progress.