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Resonance. Lecture 32 November 21, 2008. Robert Hooke. “ ceiiinosssttuv ” Anagram for “ ut tensio , sic vis ” “as the extension, so the force”. Workbook Problems due Friday. Problems 14-1 through 8, pages 14-1 -- 5. Energy in Simple Harmonic Motion. Pendulum. Point mass on a string.
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Resonance Lecture 32 November 21, 2008
Robert Hooke • “ceiiinosssttuv” • Anagram for “uttensio, sic vis” • “as the extension, so the force”
Workbook Problems due Friday • Problems 14-1 through 8, pages 14-1 -- 5
Pendulum Point mass on a string
Physical Pendulum d L Center of gravity θ
Damped Harmonic Motion Friction rears its ugly head!
Problem 14.15 A) When the displacement of a mass on a spring is ½A, what fraction of the mechanical energy is kinetic energy and what fraction is potential?
B) At what displacement as a fraction of A, is the energy half kinetic and half potential?
Problem 14.30 The center of gravity of a lower leg of a cadaver which had a mass of 5kg was located 18cm from the knee. When pivoted at the knee , the oscillation frequency was 1.6Hz. What is the moment of inertia of the lower leg?
Problem 14.33 • The amplitude of an oscillator decreases to 36.8% of it initial value in 10.0s. What is the time constant?
The period of the oscillator is • 1s • 2s • 5s • 10s
The velocity is zero when t = • 1.25 s • 2.60 s • 5.2s • 0.0 s
The acceleration is max when t= • 0.00s • 1.25 s • 4.0 s • None of the above
The velocity is a maximum for t = • 0.0s • 1.25s • 2.6s • 4.0s
Problem 14. 37 • A 25 kg child sits on a 2.0m long rope swing. To maximize the amplitude of the swinging, how much time should be between pushes?
Problem 14.32 A thin, circular hoop with a radius of 0.22m is hanging from its rim on a nail. When pulled to one side and released, the hoop swings back and forth. The moment of inertia for a hoop with the axis passing through the circumference is I = 2MR2. What is the period of oscillation?
Exam IV Wednesday, December 3 Chapter 10 and 14 Quick Review Monday