9TH GRADE PRACTICE
Physics Problems: Mechanical vibrations, Grade 9
Pendulums, harmonic, free and forced vibrations.
Here the conditions and analysis of the solution can be read without an account. In the simulator, you need to collect the same analyzes yourself: “Given,” formulas, order of steps and answer.
Problem statements
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Problem #28
Oscillation parameters and pendulumsEvaluate the statement: The system is capable of repeatedly moving around a stable equilibrium position due to restoring forces and inertia.
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The pendulum and the mass on the spring exchange kinetic and potential energy.
Answer
Problem #29
Oscillation parameters and pendulumsEvaluate the statement: the concept “Amplitude, period and frequency” means: A mathematical pendulum models a small body on a string, and a spring pendulum models a load connected to an elastic spring.
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Period and frequency are reciprocal; parameters are measured over several oscillations to reduce the relative error.
Answer
Problem #30
OscillationsThe pendulum completed 20 complete oscillations in 10 s. Find the period and frequency.
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Answer
Problem #31
Harmonic, damped and forced oscillationsEvaluate the statement: Damped oscillations lose amplitude due to resistance, while forced oscillations are supported by an external periodic force.
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After the transition process, the forced system oscillates with the frequency of the external influence.
Answer
Problem #32
Harmonic, damped and forced oscillationsEvaluate the statement: the concept of “Harmonic oscillations” means: A sharp increase in the amplitude of forced oscillations when the external and natural frequencies are close.
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The phase specifies the state of the oscillatory system at a selected moment and allows you to compare several oscillations.
Answer
Problem #33
OscillationsThe natural frequency of the system is 5 Hz. At what frequency of a weak periodic force is the largest steady-state amplitude expected?
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Resonance occurs when the frequency of influence is close to the natural frequency.
Answer
The theory behind these problems
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Formulas by topic
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