All 7 Chapters Covered
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SOLUTIONS
, Contents
1 Free Oscillations of a Linear Oscillator
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1.2 Review of the Principal Formulas ....................................................... 5
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1.3 Questions and Problems with Answers and Solutions ........................ 6
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1.3.1 Free Undamped Oscillations ..................................................... 6
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1.3.2 Damped Free Oscillations ....................................................... 11
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1.3.3 Non-oscillatory Motion of the System .................................. 15
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2 Torsion Spring Oscillator with Dry Friction
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2.2 Review of the Principal Formulas ..................................................... 21
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2.3 Questions and Problems with Answers and Solutions ...................... 22
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2.3.1 Damping Caused by Dry Friction ....................................... 22
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2.3.2 Influence of Viscous Friction ................................................ 26
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3 Forced Oscillations in a Linear System
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3.4 Review of the Principal Formulas ..................................................... 31
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3.5 Questions and Problems with Answers and Solutions ...................... 32
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3.5.1 Steady-state Forced Oscillations.............................................. 32
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3.5.2 Transient Processes ................................................................. 44
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4 Square-wave Excitation of a Linear Oscillator
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4.8 Review of the Principal Formulas ..................................................... 59
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4.9 Questions and Problems with Answers and Solutions ...................... 60
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4.9.1 Swinging of the Oscillator at Resonance ............................ 60
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4.9.2 Non-resonant Forced Oscillations ........................................... 69
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5 Parametric Excitation of Oscillations
v g v g v g 75
5.4 Questions and Problems with Answers and Solutions ...................... 75
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5.4.1 Principal Parametric Resonance ............................................. 75
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5.4.2 Manual Control of the Parameter ......................................... 90
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5.4.3 Parametric Resonances of High Orders................................. 91
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, 4 CONTENTS
6 Sinusoidal Modulation of the Parameter
vg vg vg vg 103
6.4 Questions and Problems with Answers and Solutions..................... 103
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6.4.1 Principal Parametric Resonance............................................ 103
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6.4.2 The Principal Interval of Parametric Resonance................ 109
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6.4.3 The Second Parametric Resonance ...................................... 113
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7 Free Oscillations of the Rigid Pendulum
v g v g v g v g 115
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7.5 Review of the Principal Formulas ................................................... 115
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7.6 Questions and Problems with Answers and Solutions..................... 116
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7.6.1 Small Oscillations of the Pendulum .................................. 116
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7.6.2 Oscillations with Large Amplitudes ................................... 121
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7.6.3 The Rotating Pendulum ....................................................... 133
vg vg
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K25515_SM_Cover.indd 16/12/14 v g 5:41
, Chapter 1 v g
Free Oscillations of a Linear vg vg vg vg
Oscillator
vg
1.2 Review of the Principal Formulas
vg vg vg vg
The differential equation of a free linear torsion oscillator:
vg vg vg vg vg vg vg vg
ϕ¨ + 2γϕ˙ +0 ω 2ϕ = 0.
vg vg vg vg vg vg (1.1)
vg The frequency and the period of free oscillations without friction (at γ
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vg ≪ ω0):vg √ v
g
D 2π vg
ω0 = vg vg , T0 = vg vg . (1.2)
J ω0
An oscillatory solution (valid at γ < ω0):
vg vg vg vg vg v g vg
γt
ϕ(t) = A0e − vg vg vg cos(ω 1t + δ0), vg vg (1.3)
where the constants A0 and δ0 are determined by the initial conditions ϕ(0), ϕ˙(0).
vg vg vg vg vg vg vg vg vg vg vg vg vg
The frequency ω1 of damped oscillations
vg vg vg vg vg
√
ω1 = ω 2 − γ2. (1.4)
0 v g vg vg vg
An equivalent form of the general solution:
vg vg vg vg vg vg
− γt
ϕ(t) v g= e (C cos ω 1t + S sin ω 1t),
vg vg vg vg vg vg (1.5)
where the constants C and S are determined by the initial conditions.
vg vg vg vg vg vg vg vg vg vg vg
They are related to A0 and δ0:
vg vg vg vg vg vg vg
√
A0 =
v g C 2 + S 2,
v g
v g
vg tan δ 0 = −S/C. (1.6) vg vg vg
5
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K25515_SM_Cover.indd 16/12/14 v g 5:41
vg vg vg
SOLUTIONS
, Contents
1 Free Oscillations of a Linear Oscillator
v g v g v g v g 5 v g
1.2 Review of the Principal Formulas ....................................................... 5
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1.3 Questions and Problems with Answers and Solutions ........................ 6
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1.3.1 Free Undamped Oscillations ..................................................... 6
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1.3.2 Damped Free Oscillations ....................................................... 11
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1.3.3 Non-oscillatory Motion of the System .................................. 15
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2 Torsion Spring Oscillator with Dry Friction
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2.2 Review of the Principal Formulas ..................................................... 21
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2.3 Questions and Problems with Answers and Solutions ...................... 22
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2.3.1 Damping Caused by Dry Friction ....................................... 22
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2.3.2 Influence of Viscous Friction ................................................ 26
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3 Forced Oscillations in a Linear System
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3.4 Review of the Principal Formulas ..................................................... 31
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3.5 Questions and Problems with Answers and Solutions ...................... 32
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3.5.1 Steady-state Forced Oscillations.............................................. 32
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3.5.2 Transient Processes ................................................................. 44
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4 Square-wave Excitation of a Linear Oscillator
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4.8 Review of the Principal Formulas ..................................................... 59
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4.9 Questions and Problems with Answers and Solutions ...................... 60
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4.9.1 Swinging of the Oscillator at Resonance ............................ 60
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4.9.2 Non-resonant Forced Oscillations ........................................... 69
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5 Parametric Excitation of Oscillations
v g v g v g 75
5.4 Questions and Problems with Answers and Solutions ...................... 75
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5.4.1 Principal Parametric Resonance ............................................. 75
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5.4.2 Manual Control of the Parameter ......................................... 90
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5.4.3 Parametric Resonances of High Orders................................. 91
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K25515_SM_Cover.indd 16/12/14 v g 5:41
, 4 CONTENTS
6 Sinusoidal Modulation of the Parameter
vg vg vg vg 103
6.4 Questions and Problems with Answers and Solutions..................... 103
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6.4.1 Principal Parametric Resonance............................................ 103
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6.4.2 The Principal Interval of Parametric Resonance................ 109
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6.4.3 The Second Parametric Resonance ...................................... 113
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7 Free Oscillations of the Rigid Pendulum
v g v g v g v g 115
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7.5 Review of the Principal Formulas ................................................... 115
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7.6 Questions and Problems with Answers and Solutions..................... 116
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7.6.1 Small Oscillations of the Pendulum .................................. 116
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7.6.2 Oscillations with Large Amplitudes ................................... 121
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7.6.3 The Rotating Pendulum ....................................................... 133
vg vg
@@SSeeisismmici icsisoolalati toionn
K25515_SM_Cover.indd 16/12/14 v g 5:41
, Chapter 1 v g
Free Oscillations of a Linear vg vg vg vg
Oscillator
vg
1.2 Review of the Principal Formulas
vg vg vg vg
The differential equation of a free linear torsion oscillator:
vg vg vg vg vg vg vg vg
ϕ¨ + 2γϕ˙ +0 ω 2ϕ = 0.
vg vg vg vg vg vg (1.1)
vg The frequency and the period of free oscillations without friction (at γ
vg vg vg vg vg vg vg vg vg vg vg
vg ≪ ω0):vg √ v
g
D 2π vg
ω0 = vg vg , T0 = vg vg . (1.2)
J ω0
An oscillatory solution (valid at γ < ω0):
vg vg vg vg vg v g vg
γt
ϕ(t) = A0e − vg vg vg cos(ω 1t + δ0), vg vg (1.3)
where the constants A0 and δ0 are determined by the initial conditions ϕ(0), ϕ˙(0).
vg vg vg vg vg vg vg vg vg vg vg vg vg
The frequency ω1 of damped oscillations
vg vg vg vg vg
√
ω1 = ω 2 − γ2. (1.4)
0 v g vg vg vg
An equivalent form of the general solution:
vg vg vg vg vg vg
− γt
ϕ(t) v g= e (C cos ω 1t + S sin ω 1t),
vg vg vg vg vg vg (1.5)
where the constants C and S are determined by the initial conditions.
vg vg vg vg vg vg vg vg vg vg vg
They are related to A0 and δ0:
vg vg vg vg vg vg vg
√
A0 =
v g C 2 + S 2,
v g
v g
vg tan δ 0 = −S/C. (1.6) vg vg vg
5
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K25515_SM_Cover.indd 16/12/14 v g 5:41