# Physics

When a 65 kg person climbs into a 1000 kg car, the car's springs compress vertically by 3.1 cm. What will be the frequency of vibration when the car hits a bump? Ignore damping.

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1. 65*9.8 = 637 Newtons weight
so
k = weight/deflection = 637/.031 = 20548 Newtons/meter
now the vibration problem
mass = 1068
k = 20548

You probably know about sqrt (k/m) but
F = m a = -kx
if x = A sin2pif t
v = 2pif Acos 2pif t
a = -(2pif)^2 A sin2pift
so
-m(2pif)^2 A sin 2pift = -kAsin 2pift
or
(2 pi f)^2 = k/m
f = (1/2pi) sqrt(k/m)

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2. blargh

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3. Thoust claim is forsaken, please revise and realize. <p>Hi</p>

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4. asd

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5. I can make a better physics response by just looking up this question

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6. sdsaf

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7. safsafafsaf

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