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## Homework Statement

A 440 g block on a frictionless surface is attached to a rather limp spring of constant k = 8.7 N/m. A second block rests on the first, and the whole system executes simple harmonic motion with a period of 1.4 s. When the amplitude of the motion is increased to 35 cm, the upper block just begins to slip. what is the coefficient of static friction between the blocks?

*mass of block on top is not given

## Homework Equations

see below

## The Attempt at a Solution

this is what i've done thus far

m1 = 440g = 0.44kg

m2 = ?

k = 8.7n/m

T(period) = 1.4s

A(amplitude) = 35cm = 0.35m

omega = angular velocity

using T = 2pi/omega --> gives omega = 4.48 m/s

using omega = sqrt(k/m) ---> where m = m1 + m2 = 0.44kg + m2 ---> solve for m2 = -0.0065 kg

that is impossible, negative mass? what am i doing wrong? one i get m2 i'll be able to figure mu static by comparing static friction force to force = ma

thanks