How Accurate Are These Calculations for Simple Harmonic Motion?

[nyyfan0729]

A block of mass 0.5kg moving on a horizontal frictionless surface at 2.0 m/s collides with and sticks to a massless pan attached to the end of a horizontal ideal spring whose spring constan is 32 N/m.
a) Determine the function for x(t), the displacement from equilibrium position as a function of time.
I got this to be x(t) = .25sin(8t)

b) What is the period T, of the subsequent oscillations?
I got the period to be .785 sec

c) What is the kinetic energy of the mass 4.0 sec after it collides with the spring?
I got this to be .997j

d) What force is exerted by the spring on the block at t=1.2 sec? Which way is the block moving? Explain
I got the force to be -1.334N

ARE MY ANSWERS RIGHT, I ALSO SAID THAT Xo=0m when using my equation.

 

[Hootenanny]

You have to show your working, it is much easier to check for systematic errors, you can't expect someone to work through your problems from scratch.