# Spring mechanics question easy

## Homework Statement

A block of mass m1 = 8 kg hangs from the ceiling on an ideal, massless spring with spring constant k = 65 N/m. With the block hanging on the spring, the total length of the spring is L = 3.5 m. When a second block with an identical mass of m2 = 8 kg is tied to the first with a massless string, the spring stretches an additional h0 = 1.5 m.

The string is cut so that mass m2 falls away. What is the maximum velocity of mass m1?

## The Attempt at a Solution

$$\frac{kx^2}{2}=\frac{mv^2}{2}$$
x=1.5 and solving for v gives 4.3

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tiny-tim
Homework Helper
Hi ronaldor9! … With the block hanging on the spring, the total length of the spring is L = 3.5 m. When a second block with an identical mass of m2 = 8 kg is tied to the first with a massless string, the spring stretches an additional h0 = 1.5 m.

x=1.5 and solving for v gives 4.3
you have to (find and) add on the bit of x that's already in the 3.5. 