 #1
yesmale4
 40
 1
 Homework Statement:

A solid block of mass m2 = 3.3 kg, at rest on a horizontal frictionless surface, is connected to a relaxed spring. The other end of the spring is fixed, and the spring constant is k = 60 N/m. Another solid block of mass m1 = 4.9 kg and speed v1 = 8.2 m/s collides with the 3.3 kg block. The blocks stick together, and compress the spring.
the maximum compression of the spring is 1.8115 m.
What is the magnitude of the acceleration of the two blocks when the spring is at maximum compression?
 Relevant Equations:

f=ma
m1v1=U(m1+m2)
i would like to get some help and to understand why my answer is incorrect , here is how i did the first and second part.
about the first part i did it right but i don't understand what I am doing wrong in the second part i tried k and i get 23.997 and i also try +k and i get 23.997 but they bout wrong .
i hope for some help