(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A block of mass m1=1.88 kg slides along a frictionless table with a speed of 10.3 m/s. Directly in front of it, and moving in the same direction, is a block m2=4.92 kg moving at 3.27 m/s. A massless spring with a force constant k=1120N/m is attached to the backside of m2. When the blocks collide, what is the maximum compression of the spring? (Hint: at the moment of maximum compression of the spring, the two blocks move as one, find the velocity by noting that the collision is compltely inelastic to this point).

2. Relevant equations

m1v1+m2v2=(m1+m2)vf

1/2(m1+m2)Vf^2=1/2Kx^2

3. The attempt at a solution

I solved for vf in the inelastic equation:

vf = (m1v1 + m2v2) / (m1 + m2)

and plugged it into the energy equation and solved for x:

[(m1v1 + m2v2)^2 / K(m1 + m2)]^1/2 = x

Plugged in numbers:

{[1.88(10.3) + 4.92(3.27)]^2 / 1120(1.88 + 4.92)}^1/2 = x

(1257/7620)^1/2 = x

x = .407 m = 40.7 cm

The book got 35.9 cm. Can anyone find my mistake, or if I did it completely wrong, can anyone tell me how to do it? Thanks in advance!

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# Homework Help: Completely Inelastic Collisions

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