Determine the period and frequency of a string pendulum of length $1\,\text{m}$. How many oscillations will he make in $30\,\text{s}$?

T = 2\,\text{s}; \nu = 0{,}5\,\text{Hz}; n = 15

Weight of the spring pendulum $40\,\text{g}$, spring stiffness $20\,\text{N/m}$. Define period, frequency and time $25$ hesitation.

T = 0{,}28\,\text{c}; \nu = 3{,}56\,\text{Hz}; t = 7\,\text{s}

Load weight $2\,\text{kg}$ fluctuates on a spring stiffness $50\,\text{N/m}$ with amplitude $5\,\text{sm}$. Determine possible coordinates through $0{,}15\,\text{s}$ for two standard initial phases and velocity at point $x=2\,\text{sm}$.

x_1 = 0{,}0365\,\text{m}; x_2 = 0{,}0341\,\text{m}; v = 0{,}23\,\tfrac{\text{m}}{\text{s}}

Capacitor with capacity $125\,\text{pF}$ charged to $400\,\text{V}$ and closed to a coil with inductance $20\,\text{mGn}$. Determine the period, frequency and cyclic frequency, maximum charge and current, write down the dependencies $q(t)$, $u(t)$ and $i(t)$.

T = 3{,}14\cdot 10^{-7}\,\text{s}; \nu = 3{,}2\cdot 10^{6}\,\text{Hz}; \omega = 2\cdot 10^{7}\,\tfrac{1}{\text{s}}; q_{\text{m}} = 5\cdot 10^{-8}\,\text{Cl}; I_{\text{m}} = 1\,\text{A}

According to what law do the voltage in the lighting network and the current in the resistor change? $500\,\text{Om}$included in this network $220\,\text{V}$, $50\,\text{Gts}$?

U_{\text{m}} = 311\,\text{B}; I_{\text{m}} = 0{,}62\,\text{A}; \omega = 314\,\tfrac{1}{\text{s}}

The capacitor was given a charge $4\cdot10^{-4}\,\text{Kl}$ and shorted it to the coil. Capacity $5\,\text{mkF}$, inductance $32\,\text{mGn}$. Determine the cyclic frequency, voltage and current amplitudes and the laws of their change.

\omega = 2500\,\tfrac{1}{\text{s}}; U_{\text{m}} = 80\,\text{B}; I_{\text{m}} = 1\,\text{A}

In an oscillatory circuit, the frequency $2\cdot10^{5}\,\text{Gts}$, inductance $1{,}5\,\text{mGn}$, current amplitude $0{,}2\,\text{A}$. Determine the capacitance and voltage amplitude.

C = 4{,}2\cdot 10^{-10}\,\text{F}; U_{\text{m}} = 378\,\text{B}

In AC circuit voltage $24\,\text{V}$ and frequency $200\,\text{Gts}$ capacitor is turned on. What is its capacity if the current is $0{,}8\,\text{A}$?

C = 2{,}65\cdot 10^{-5}\,\text{F}

In AC circuit voltage $12\,\text{V}$ and frequency $400\,\text{Gts}$ included steel conductor length $10\,\text{m}$ and cross section $0{,}6\,\text{mm}^{2}$. Determine the amplitudes of voltage and current and the law of their change.

U_{\text{m}} = 17\,\text{B}; I_{\text{m}} = 8{,}5\,\text{A}; \omega = 2512\,\tfrac{1}{\text{s}}

Period of oscillation in a wave $0{,}16\,\text{s}$, wave speed $3\,\text{m/s}$. Determine length, frequency and time $25$ hesitation.

\lambda = 0{,}48\,\text{m}; \nu = 6{,}25\,\text{Hz}; t = 4\,\text{c}

Two common mode generators operate at a frequency $1{,}5\,\text{MGts}$. What is the result of interference at the point for which the path difference $650\,\text{m}$?

\dfrac{\Delta d}{\lambda/2} = 6{,}5\ \text{— neither maximum, neither minimum}

Wavelength of the Krasnoyarsk radio station $1{,}5\,\text{km}$. What is the frequency and how many oscillations occur per $0{,}2\,\text{ms}$? What is the frequency of a sound wave with period $0{,}2\,\text{ms}$?

\nu = 2\cdot 10^{5}\,\text{Hz}; n = 40; \nU_{\text{z}} = 5\cdot 10^{3}\,\text{Hz}

The radar operates on a wave $6\,\text{sm}$ and radiates $1250$ pulses per second duration $4\,\text{mks}$. How many oscillations does a pulse contain and what is the longest reconnaissance range?

n = 20\,000; R_{\text{m}} = 120\,000\,\text{m}

Distance between nodes of a standing electromagnetic wave $12\,\text{m}$. What are the wavelength and frequency?

\lambda = 24\,\text{m}; \nu = 1{,}25\cdot 10^{7}\,\text{Hz}

Two common-mode electromagnetic wave generators operate at a frequency $2{,}5\cdot10^{8}\,\text{Gts}$. What is the result of interference at a point with a path difference $3\,\text{m}$?

\dfrac{\Delta d}{\lambda/2} = 5\ \text{— minimum}

Wavelength of light in water $450\,\text{nm}$. What is the frequency, wavelength in air and color of the rays? Accept $n_{\text{vody}}=1{,}33$.

\lambda = 600\cdot 10^{-9}\,\text{m}; \nu = 5\cdot 10^{14}\,\text{Hz}\ \text{(orange)}

Determine the frequency of radiation with wavelength $1{,}5\cdot10^{-7}\,\text{m}$. What is the physical meaning of frequency?

\nu = 2\cdot 10^{15}\,\text{Hz}

11TH GRADE PRACTICE

Physics Problems: Oscillations and waves, Grade 11

Mechanical, electromagnetic vibrations and wave connections.

30 problems across 3 sub-topics

Practise in the interactive mode

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

The answer options are there to check against, and the walkthrough opens under each problem.

30 problems

Position in this set: 1 from 30

Problem #12

Mechanical vibrations

Determine the period and frequency of a string pendulum of length . How many oscillations will he make in ?

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Given

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Answer

Position in this set: 2 from 30

Problem #13

Mechanical vibrations

Weight of the spring pendulum , spring stiffness . Define period, frequency and time hesitation.

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Answer

Position in this set: 3 from 30

Problem #14

Mechanical vibrations

When a load of mass is suspended from a spring , she stretched out on . Determine the frequency of vibration of the load.

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Given

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The mass contracts - the period depends only on the stretching of the spring.

Answer

Position in this set: 4 from 30

Problem #15

Mechanical vibrations

For spring pendulum made hesitation. Determine the mass of the load if the spring stiffness . Is there enough data to find a path in the first at amplitude ?

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Answer

Position in this set: 5 from 30

Problem #16

Mechanical vibrations

Load weight fluctuates on a spring stiffness with amplitude . Determine possible coordinates through for two standard initial phases and velocity at point .

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Given

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Counting from the extreme position.
Counting from the equilibrium position.

Answer

Position in this set: 6 from 30

Problem #17

Electromagnetic vibrations

Capacitor with capacity charged to and closed to a coil with inductance . Determine the period, frequency and cyclic frequency, maximum charge and current, write down the dependencies , and .

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Given

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Thomson's formula.
Oscillation equations: q = q_m cos ωt, u = U_m cos ωt, i = I_m cos(ωt + π/2).

Answer

Position in this set: 7 from 30

Problem #18

Electromagnetic vibrations

According to what law do the voltage in the lighting network and the current in the resistor change? included in this network , ?

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Given

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The network indicates the effective voltage value.
Laws: u = 311 sin 314t (B), i = 0.62 sin 314t (A).

Answer

Position in this set: 8 from 30

Problem #19

Electromagnetic vibrations

To the network , turned on the capacitor . Determine the amplitude voltage and current, as well as the law of change of current. What inductance must be connected in series for resonance?

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Given

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With such inductance, resonance will occur - this is precisely what should be avoided.

Answer

Position in this set: 9 from 30

Problem #20

Electromagnetic vibrations

The capacitor was given a charge and shorted it to the coil. Capacity , inductance . Determine the cyclic frequency, voltage and current amplitudes and the laws of their change.

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Given

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Laws: q = 4·10⁻⁴ cos 2500t (C), u = 80 cos 2500t (B), i = cos(2500t + π/2) (A).

Answer

Position in this set: 10 from 30

Problem #21

Electromagnetic vibrations

In an oscillatory circuit, the frequency , inductance , current amplitude . Determine the capacitance and voltage amplitude.

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Given

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We expand Thomson's formula with respect to capacity.
The energy of the capacitor at maximum is equal to the energy of the coil at maximum.

Answer

Position in this set: 11 from 30

Problem #22

Electromagnetic vibrations

In AC circuit voltage and frequency capacitor is turned on. What is its capacity if the current is ?

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Given

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Answer

Position in this set: 12 from 30

Problem #23

Electromagnetic vibrations

In AC circuit voltage and frequency included steel conductor length and cross section . Determine the amplitudes of voltage and current and the law of their change.

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Given

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Laws: u = 17 sin 2512t (V), i = 8.5 sin 2512t (A) - across the resistor, the current and voltage are in phase.

Answer

Position in this set: 13 from 30

Problem #24

Electromagnetic vibrations

Coil inductor included in the alternating current circuit. What is the frequency if at voltage the current is ?

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Given

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Answer

Position in this set: 14 from 30

Problem #25

Waves

For mosquito wings make hesitation. Determine the frequency and period, as well as the length of the sound wave at speed .

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Given

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Answer

Position in this set: 15 from 30

Problem #26

Waves

Period of oscillation in a wave , wave speed . Determine length, frequency and time hesitation.

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Given

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Wavelength is the path a wave travels in one period.

Answer

Position in this set: 16 from 30

Problem #27

Waves

The observer saw lightning, and through heard thunder. How long can a thunderstorm be expected if the wind speed , and the speed of sound ?

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Given

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The light arrives almost instantly, so the delay is the travel time of the sound.

Answer

Position in this set: 17 from 30

Problem #28

Waves

Two common mode generators operate at a frequency . What is the result of interference at the point for which the path difference ?

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Given

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The number is not an integer: the path difference is not equal to either an integer number of wavelengths (maximum) or an odd number of half-wavelengths (minimum).

Answer

Position in this set: 18 from 30

Problem #29

Waves

Wavelength of the Krasnoyarsk radio station . What is the frequency and how many oscillations occur per ? What is the frequency of a sound wave with period ?

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Given

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Answer

Position in this set: 19 from 30

Problem #30

Waves

Distance to plane . How long does it take for an electromagnetic pulse to travel to the plane and back?

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Given

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The impulse travels the distance twice: back and forth.

Answer

Position in this set: 20 from 30

Problem #31

Waves

The radar operates on a wave and radiates pulses per second duration . How many oscillations does a pulse contain and what is the longest reconnaissance range?

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Given

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So many oscillations fit into one impulse.

Answer

Position in this set: 21 from 30

Problem #32

Waves

What wavelength is the receiver tuned to if the oscillating circuit has a capacitance and inductance ?

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Given

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Answer

Position in this set: 22 from 30

Problem #33

Waves

Distance between nodes of a standing electromagnetic wave . What are the wavelength and frequency?

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Given

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Adjacent nodes of a standing wave are separated by half the wavelength.

Answer

Position in this set: 23 from 30

Problem #34

Waves

For the string commits hesitation. How will a sound wave behave when it encounters an obstacle the size ?

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Given

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The wavelength is smaller than the size of the obstacle, so diffraction is invisible and the wave is reflected.

Answer

Position in this set: 24 from 30

Problem #35

Waves

Two common-mode electromagnetic wave generators operate at a frequency . What is the result of interference at a point with a path difference ?

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Given

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An odd number of half-waves means there is a minimum at this point.

Answer

Position in this set: 25 from 30

Problem #36

Waves

With what maximum frequency should radar pulses follow when reconnaissance of targets up to ?

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Given

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The next impulse cannot be sent before the previous one returns.

Answer

Position in this set: 26 from 30

Problem #39

Waves

What is one light year equal to?

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Given

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A light year is a distance, not a time.

Answer

Position in this set: 27 from 30

Problem #40

Waves

How long does light take from the Sun to Pluto if the distance is ?

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Given

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Answer

Position in this set: 28 from 30

Problem #50

Waves

How do the wavelength, frequency and speed of red light change when passing from air to glass with , if ?

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Given

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The frequency is determined by the source and does not change when moving to another medium.

Answer

Position in this set: 29 from 30

Problem #51

Waves

Wavelength of light in water . What is the frequency, wavelength in air and color of the rays? Accept .

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Given

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The wave is longer in air than in water: it is orange light.

Answer

Position in this set: 30 from 30

Problem #53

Waves

Determine the frequency of radiation with wavelength . What is the physical meaning of frequency?

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Given

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Frequency shows how many oscillations a wave makes per second.

Answer

The theory behind these problems

Work through the topic if a problem will not give in.

Mechanical vibrationsPeriod, frequency, phase, speed, acceleration and energy.Electromagnetic vibrations and alternating currentOscillatory circuit, reactance and transformer.WavesLength, speed, frequency, phase and reflected signal.

Formulas by topic

Look up symbols and units of measurement in the reference.

AmplitudeA, xₘ · m Spring stiffnessk · N/m PeriodT · with Velocityv · m/s Frequencyν · Hz Cyclic frequencyω · s⁻¹ EnergyE, W · J