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x(t)= A cos( (k/m)^(1/2) * t)

A block of mass m is attached to a spring whose spring constant is k. The other end of the spring is fixed so that when the spring is unstretched, the mass is located at x=0. View Figure . Assume that the +x direction is to the right.

The mass is now pulled to the right a distance A beyond the equilibrium position and released, at time t=0, with zero initial velocity.

and asks

At what time t_1 does the block come back to its original position for the first time?

Express your answer in terms of k and m.

So when t=0

cos( (k/m)^(1/2) * 0) = 1

so at t_1

cos( (k/m)^(1/2) * t_1) = 1

so

(k/m)^(1/2) * t_1 = 2pi

so t_1 = 2pi(m/k)^(1/2)

but when i submit it it says it's off by a multiplicative factor!!!!!

what's wrong with that?

thanks,

adam

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# Homework Help: Simple harmonic motion for block of mass

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