Need help going over a momentum/spring problem

[groundhog92]

1.Homework Statement
A pellet gun is fired into a block of wood that is attached to a spring on a frictionless surface. The bullet remains in the wood and the block of wood and the bullet enter into a simple harmonic motion with Amplitude=11cm. The 5g bullet was traveling at 650m/s before hitting the 2.5kg block of wood.
a)What is the spring constant?
b)What is the the total energy of the system after the collision?
c)What is the max acceleration of the bullet/block once it begins its oscillation?
d)Where will the bullet/block reach a velocity of 0?

Homework Equations

mv=mv
(1/2)mv^2=(1/2)kx^2
a=(V^2)/A
v=2pief(sqrt(A^2-x^2))

The Attempt at a Solution

I've already done the problem I just need someone to check my work because I'm not completely sure about the process.

Part a
(.005)(650)=(2.505)v
v=1.3m/s

(1/2)k(.11^2)=(1/2)(2.505)(1.3^2)
k=349.9N/m

Part b
E=(1/2)mv^2 + (1/2)kx^2
E=((2.505)(1.3^2)+(349.9)(.11^2))/2
E=4.23J

Part c
a=(v^2)/A
a=(1.3^2)/.11
a=15.4m/s^2

Part d
Where A=x
so where x=+-11cm

Thanks in advance for any help.

 

[davieddy]

In part b) you have added the max KE to the max PE.
When KE is max, PE is zero and vice versa.

 

[groundhog92]

So the total energy of the system would be equal to just the max potential or kinetic by themselves?

 

[davieddy]

Yep!

 

[groundhog92]

alright thanks