Decisions Control №1 in physics at Remizov AN "Medical Physics" PART I Mechanics.
The file provides solutions to Part I. The files jpg - solution to problems. The doc - answers to the theory. Answers to the theory chosen from several textbooks and secondary sites.
Task 1: Examine the textbook AN Remizov § 7.1 Solve the problem.
Body weight m = 1 kg attached to the horizontal spring stiffness
k = 1 (the second end of the spring is secured in position) is at rest and the spring was initially unstrained. Then the body of said certain speed, and it deviated from the initial position by an amount A = 0.01 m in the positive direction of the coordinate axes. Record differential equation of motion of the body, a spring attached to the - first in general terms and then substituting specific numerical values. Write the solution of this differential equation and build his schedule. Formulate and write a definition and physical meaning of the basic characteristics of the harmonic oscillation amplitude, period, frequency, cycle frequency, phase, and the initial phase.
Problem 2. Study the textbook AN Remizov § 7.5. Solve the problem.
Oscillatory system, considered in the previous problem, oscillates in a viscous medium - in conjunction with the elastic force of her force of resistance of the medium, the magnitude of which is directly proportional to the velocity of the body. The coefficient of proportionality
r = 0.01. Write a differential equation of damped oscillations - first in general and then substituting specific numerical values. Write the solution of this differential equation and build his schedule. Find logarithmic decrement.
Objective 3. Study the textbook AN Remizov § 7.6. Solve the problem.
On oscillatory systems considered in the problem number 2, operates the external driving force, changing the law (H). Write a differential equation of oscillations - first in general and then with the substitution of numerical data; calculate the amplitude fluctuations and write the solution of this differential equation. At what frequency external driving forces in the response come?
Task 4. Learn textbook AN Remizov § 7.4. Answer the questions.
What is a complex periodic oscillation? Give a mathematical formulation and recording of the Fourier theorem. What are harmonics? What are their characteristics? How to calculate the frequency of vibrations of the complex, which must be a multiple of the frequency of the harmonics?
Draw a graph of complex periodic oscillation, which is the sum of two harmonic oscillations and. Present under each other graphics; ; = +. Sketch the spectrum of the complex periodic oscillations.
Task 5. Explore textbook AN Remizov §§ 7.8, 7.9. Solve the problem.
Source plane harmonic wave oscillates according to the law. What law oscillates point spaced at a distance of 1 m from the source, if the speed of the wave. What is the wavelength? What is it in this case? Find the average power density of this wave, believing that it is distributed in the water
Task 6. Explore textbook AN Remizov §§ 8.1, 8.2. Answer the questions.
6a. What is sound? Considering the speed of sound in air equal to 340 m / s, find the minimum and maximum wavelength of sound in air.
6b. What is the level of intensity of the sound, for some formula can be found in decibels? Solve the problem: the initial intensity of the harmonic sound signal 10 times greater than the threshold for frequency present in the formula for calculating the level of intensity and equal. What is the level of intensity of the sound? What will be the level of intensity if the intensity of the signal itself will increase from said entry-level 1,000 times? What should be the frequency of the signal to increase the intensity level in dB was exactly equal to the increase in the volume of backgrounds?
Problem 7. Examine textbook AN Remizov § 8.6. Answer the questions.
7a. What is the frequency range of the ultrasonic waves (ultrasound)? What is the maximum length of the ultrasonic wave in the air (). What features of ultrasound due to its short wavelength?