Presentation on theme: "Resonance Lecture 32 November 21, 2008. Robert Hooke “ceiiinosssttuv” Anagram for “ut tensio, sic vis” “as the extension, so the force”"— Presentation transcript:
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
Energy in Simple Harmonic Motion
Pendulum Point mass on a string
Physical Pendulum θ Center of gravityL d
Damped Harmonic Motion Friction rears its ugly head!
Damped Harmonic Motion
Problem 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 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 The amplitude of an oscillator decreases to 36.8% of it initial value in 10.0s. What is the time constant?
The period of this oscillator is approximately
The period of the oscillator is 1.1s 2.2s 3.5s 4.10s
The is zero at t = ?? approximately
The velocity is zero when t = s s 3.5.2s s
The acceleration is a maximum when t = ??
The acceleration is max when t= s s s 4.None of the above
The velocity is a maximum for t = ??
The velocity is a maximum for t = 1.0.0s s 3.2.6s 4.4.0s
Problem 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 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 = 2MR 2. What is the period of oscillation?
Exam IV Wednesday, December 3 Chapter 10 and 14 Quick Review Monday