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I'm having trouble with this problem because I don't know how to deal with all these unknowns:

4. A block attached to a spring with unknown spring constant oscillates with a period of 2.0 s. What is the period if :

a. The mass is doubled?

b. The mass is halved?

c. The amplitude is doubled?

d. The spring constant is doubled?

I think I should use T = 2π * sqrt( m / k ), but what are m and k... ??

Also, what relates this to amplitude?

Hopefully I'm doing this problem correctly, but I don't know how to get acceleration:

7. The bow of a destroyer undergoes simple harmonic vertical pitching motion with a period of 8.0 s and an amplitude of 2.0 m.

a. What is the maximum vertical velocity of the destroyer’s bow?

f = 1/T = .125rev/s

ω = 2πf = .785rad/s

v = ωr = (.785rad/s) (2m) = 1.57m/s

b. What is the maximum acceleration?

??

c. An 80 kg sailor is standing on a scale in the bunkroom in the bow. What are the maximum and minimum readings on the scale in newtons?

80kg * ( 9.8m/s^2 + a)

80kg * ( 9.8m/s^2 - a)

Thanks,

dusty.......

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# Homework Help: Harmonic motion unknowns

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