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rmunoz
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Homework Statement
In the figure below, block 1 (mass 1.6 kg) is moving rightward at 12 m/s and block 2 (mass 4.8 kg) is moving rightward at 2.8 m/s. The surface is frictionless, and a spring with spring constant of 1100 N/m is fixed to block 2. When the blocks collide, the compression of the spring is maximum at the instant the blocks have the same velocity. Find the maximum compression.
http://www.webassign.net/halliday8e/pc/halliday8019c09/halliday8019c09-fig-0065.htm
Homework Equations
m1(i)v1(i) + m2(i)v2(i) = m1(f)v1(f) + m2(f)v2(f)
p=mv
KE=1/2mv[tex]^{2}[/tex]
Work-spring=1/2kx[tex]^{2}[/tex]
The Attempt at a Solution
Momentum before collision:
P1+P2= Psys
m1v1 + m2v2 = Psys
1.6kg*12m/s +4.8kg*2.8m/s= 19.2 kg*m/s + 13.44 kg*m/s = 32.64 kg*m/s
work done by spring on object 1 = change in object 1's kinetic energy ?
Momentum after collision of object 1 will be negative, and momentum of object 2 will have increased in the positive direction.
Questions:
1) how do i relate the compression of the spring to the linear momentum of the system?
2) how do i tell weather or not linear momentum is conserved (in general, not just in the scope of this problem)
3) how can i relate the change in kinetic energy due to the spring to the change in the momentum of object 1 and 2? (or is that at all how i am supposed to approach this problem)
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