Simple harmonic motion Definition and 916 Threads

In mechanics and physics, simple harmonic motion (sometimes abbreviated SHM) is a special type of periodic motion where the restoring force on the moving object is directly proportional to the object's displacement magnitude and acts towards the object's equilibrium position. It results in an oscillation which, if uninhibited by friction or any other dissipation of energy, continues indefinitely.
Simple harmonic motion can serve as a mathematical model for a variety of motions, but is typified by the oscillation of a mass on a spring when it is subject to the linear elastic restoring force given by Hooke's law. The motion is sinusoidal in time and demonstrates a single resonant frequency. Other phenomena can be modeled by simple harmonic motion, including the motion of a simple pendulum, although for it to be an accurate model, the net force on the object at the end of the pendulum must be proportional to the displacement (and even so, it is only a good approximation when the angle of the swing is small; see small-angle approximation). Simple harmonic motion can also be used to model molecular vibration as well.
Simple harmonic motion provides a basis for the characterization of more complicated periodic motion through the techniques of Fourier analysis.

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  1. I

    Calculating Simple Harmonic Motion for a Mass on a Spring - Homework Example

    1. Homework Statement [/b] 1)For a mass on a spring,using k=10N/m,m=1kg and amplitude =0.1m.calculate the following: *The displacement 0.2s after release. *The Time-period of oscillation. *The max. Velocity. *The max acceleration. Homework Equations x=Acos\varpit (for...
  2. P

    Relate simple harmonic motion to circular motion

    1. Prove that the maximum speed of a mass on a spring is given by Vmax = 2pifA f = frequency A= amplitude We have just learned how to relate simple harmonic motion to circular motion. So I am dealing with some of those equations. 3. While writing this out I kind of had a thought and...
  3. T

    Simple Harmonic Motion MCQ Question

    Homework Statement A simple pendulum was moving in front of a horizontal scale. the extreme positions of the bob were at the 300mm and 500mm marks. The bob moved from the 350mm to the 450mm marks in 1.0s. What is the period of the oscillations? A. 2.0s B. 3.0s C. 4.0s D. 6.0s Homework...
  4. E

    Simple harmonic motion and angular frequency

    Hi everyone new here and hope i have put this in the right place? If anyone could help me with this question i would be very grateful. The value w(angular frequancy) is introduced into the analysis of simple harmonic motion A) Because the unit of hz is not a convenient unit for frequancy B)...
  5. E

    Simple Harmonic Motion Archimedes

    Homework Statement A body of uniform cross-sectional area A and mass density ρ floats in a liquid of density ρ0 (where ρ < ρ0), and at equilibrium displaces a volume V. Making use of Archimedes principle (that the buoyancy force acting on a partially submerged body is equal to the mass of the...
  6. E

    Simple harmonic motion involving circuit

    Homework Statement "A small body rests on a horizontal diaphragm of a loudspeaker which is supplied with an alternating current of constant amplitude but variable frequency. If the diaphragm executes simple harmonic oscillation in the vertical direction of amplitude 10 µm, at all frequencies...
  7. A

    Energy in Simple Harmonic Motion

    Problem: A 2.4-kg object on a frictionless horizontal surface is attached to one end of a horizontal spring of force constant k=4.5 kN/m. The other end of the spring is held stationary. The spring is strecthed 10 cm from equilibrium and released. find the system's total mechanical energy...
  8. E

    Simple harmonic motion of two springs

    Homework Statement "Two light springs have spring constants k1 and k2, respectively, and are used in a vertical orientation to support an object of mass m. Show that the angular frequency of small amplitude oscillations about the equilibrium state is [(k1 + k2)/m]^1/2 if the springs are...
  9. M

    Simple harmonic motion of the earth

    is the rotation of the Earth and the revolution of it around sun simple harmonic in nature? it is periodic but not linear.
  10. D

    Simple harmonic motion of a spring and ball

    Homework Statement a ball that has been placed on top of a coil spring with a spring constant of 575 N/m and a length (h1) of 25.0 cm. As the ball compresses the spring, it contacts a second spring that has a spring constant of 325 N/m and a length (h2) of 15.0 cm. If the ball is 12.5 cm...
  11. A

    How to Calculate Bullet Velocity in a Spring/Block System?

    Hi! Could someone please check if my following problems are correct? Any insight on why a problem is incorrect would be appreciated. Thanks! 1) An object is hung from a light vertical helical spring that subsequently stretches 2.0 cm. The body is then displaced and set in SHM. Compute the...
  12. M

    Simple Harmonic Motion (easy question)

    Homework Statement A 0.26 kg mass attached to a spring undergoes simple harmonic motion with a period of 0.84 s. What is the force constant of the spring? Homework Equations T = 2*pi*SQRT(m/k) The Attempt at a Solution I know this is supposed to be an easy question, but for some...
  13. C

    Simple Harmonic Motion and Elasticity

    Homework Statement A 0.01 kg bullet is fired horizontally into a 2.50 kg wooden block attached to one end of a massless, horizontal spring (spring constant = 845 N/m). The other end of the spring is fixed in place, and the spring is unstrained initially. The block rests on a horizontal...
  14. S

    How Does Simple Harmonic Motion Relate to Sinusoidal Functions?

    F_s=-kx=ma, a=\frac{-kx}{m} We now need to find an equation that satisfies: \frac{d^2x}{d^2t}=\frac{kx}{m} We get (letting w^2=k/m): x(t)=A*Cos(wt+\phi) The time it takes for one cycle is:T_1=2 \pi\sqrt{\frac{m}{k} Now, let's solve for T again using a different method...
  15. I

    Simple harmonic motion -> amplitude independent of mass?

    simple harmonic motion --> amplitude independent of mass? I know that acceleration is directly proportional to displacement, but opposite in sign, and that acceleration and displacement are related by the square of the frequency. But i was wondering if amplitude is independent of mass in...
  16. D

    Quick question about Simple Harmonic Motion

    I'm going to dispense with the provided template for this, I hope no one minds. I always understood that for simple harmonic motion there was this equation: \omega = \sqrt{\frac{k}{m}} However, I recently got a book that helps you study for the Physics GRE (Graduate Record Examination). There...
  17. N

    Simple harmonic motion Need help Im studying

    Homework Statement A spring, of negligible mass and which obeys Hooke's Law, supports a mass M on an incline which has negligible friction. The figure below shows the system with mass M in its equilibrium position. The spring is attached to a fixed support at P. The spring in its relaxed state...
  18. A

    The ideal spring and simple harmonic motion

    Homework Statement A person who weighs 665 N steps onto a spring scale in the bathroom, and the spring compresses by 0.67 cm. (a) What is the spring constant? (b) What is the weight of another person who compresses the spring by 0.37 cm? Homework Equations f=-Kx...
  19. W

    Simple Harmonic Motion and time calculation

    Homework Statement An object is undergoing simple harmonic motion with period 0.280 s and amplitude 5.95 cm . At t=0 the object is instantaneously at rest at x= 5.95 cm. Calculate the time it takes the object to go from x= 5.95 to x= -1.44 . Homework Equations X=A.cos(wt) ------> the...
  20. G

    Simple Harmonic Motion and hung spring

    Homework Statement A spring is hung from the ceiling. A 0.450-kg block is then attached to the free end of the spring. When released from rest, the block drops 0.150 m before momentarily coming to rest. (a) What is the spring constant of the spring? (b) Find the angular frequency of the...
  21. S

    Find position after t for simple harmonic motion

    A 28.0 kg block at rest on a horizontal frictionless air track is connected to the wall via a spring. The equilibrium position of the mass is defined to be at x=0. Somebody pushes the mass to the position x= 0.350 m, then let's go. The mass undergoes simple harmonic motion with a period of 4.70...
  22. B

    Simple harmonic motion velocity & time

    Homework Statement The velocity of an object in simple harmonic motion is given by v(t)= -(0.269 m/s)sin(15.0t + 2.00π), where t is in seconds. What is the first time after t=0.00 s at which the velocity is -0.150 m/s? Homework Equations already given in question The Attempt at a...
  23. J

    How Far Does a Particle Travel in One Period of SHM?

    Homework Statement If a particle undergoes SHM with amplitude 0.18 m, what is the total distance it travels in one period? Homework Equations The Attempt at a Solution My physics teacher did not explain any of this to us, and I just don't know where to start!
  24. N

    Simple harmonic motion question

    Homework Statement A mass of 10g is suspended from a spring of unstreched length 80cm. The extension produced is 1cm. The mass is pulled down a further 0.5cm and then released. Find: a) the period of motion b)the maximum speed of the mass c) the max Ke of the mass d)the tension in the...
  25. J

    Calculating Velocity in Simple Harmonic Motion: A Homework Problem

    Homework Statement While visiting friends at Cal State Chico, you pay a visit to the Crazy Horse Saloon. This fine establishment features a 200- kg mechanical bucking bull that has a mechanism that makes it move vertically in simple harmonic motion. Whether the “bull” has a rider or not, it...
  26. M

    Simple Harmonic Motion solution problem

    I've been going through and proving to myself that the solution to the SHM equation is correct; at A level we were just told what it was but never really shown why. I've gone through the problem as a standard 2nd Order ODE (with complex roots of course) and ended up at: x = A_{real}...
  27. O

    Simple Harmonic Motion and pendulum clock

    Homework Statement What will be better to take to the moon, a spring clock or a pendulum clock. Why? Homework Equations F= -k*(Delta)x k = g m/Dx T = 2*π*[square-root of:(m/k)] The Attempt at a Solution I know that there is less gravitational force while on the moon...
  28. V

    Simple harmonic motion spring question

    1. A spring with spring constant 14.5 n/m hangs from the ceiling. A 430g ball is attached to the spring and allowed to come to rest. It is then pulled down 7.20cm and released. What is the time constant if the ball's amplitude has decreased to 3.70 after 52.0 oscillations? The...
  29. C

    Simple harmonic motion and buoyant force

    Homework Statement A cylindrical wooden log is loaded with lead at one end so that it floats upright in water. The length of the submerged portion is L = 2.56m. The log is set into vertical oscillation. (a) Show that the oscillation is simple harmonic (b) Find the period of oscillation...
  30. B

    How do you determine the amplitude of a wave exhibiting simple harmonic motion?

    When a string, fixed at both ends, has a force exerted on it, how do you determine what the amplitude will be, if the tension, applied force, and length are known?
  31. V

    Conceptual Questions Fluids and Simple Harmonic motion

    Homework Statement 1. Do you use the equation of continuity and Bernoulli's equation simultaneously in a question? When do you use them? 2. In simple harmonic motion, why is the velocity shifted to left of the displacement by pi/4? Homework Equations pressure + .5density x velocity...
  32. C

    Simple Harmonic Motion: vertical springs - graphing period^2 & mass

    Homework Statement Using experimental values for mass and period of oscillations, I'm trying to graph period^{2} (y-axis) against mass (x-axis) to get a gradient = 4(pi^{2})/k so I can find k (spring constant). The problem is that when I use each pair of results in the equation below, I...
  33. M

    Help with right or wrong question in simple harmonic motion

    I have this right or wrong question in physics that i know the answer to but not the way to solve it can you help me with it?: 2 identical springs were put Vertically. if one was pulled 5cm (spring1) and the other was pulled 10cm(spring2) and were left to move a simple harmonic motion would...
  34. A

    Simple harmonic motion velocity and acceleration

    Homework Statement An oscillator consists of a block attached to a spring (k = 125 N/m). At some time t, the position (measured from the system's equilibrium location), velocity, and acceleration of the block are x = 0.800 m, v = -11.3 m/s, and a = -119 m/s2 (a) calculate the frequency of...
  35. B

    HELP PLESE Simple Harmonic Motion

    Homework Statement A mass on a spring undergoes simple harmonic motion with amplitude A. a) In a time equal to three periods, what is the magnitude of the displacement of the mass? b) In a time equal to three periods, what actual distance did it travel? Homework Equations The...
  36. D

    Simple Harmonic Motion Lab Question

    In physics class, we had to do a lab where a mass was attached vertically to a spring system. The spring went through simple harmonic motion. We stretched the mass and let go of it. We then used a software to determine the kinetic energy, the elastic potential energy, and the total energy. We...
  37. K

    Measurement of Gravity (Simple Harmonic Motion)

    Homework Statement If the slope of your gradient turns out to be 4.041 s^2.m^-1 then what value would you obtain for g? State your answer in m.s^2 and to 3 significant figures. Homework Equations T^2 = (4 pi^2 e1 / g) - (4 pi^2 e0 / g) This is the one I'm supposed to use. Other ones...
  38. D

    Calculating Energy in Simple Harmonic Motion: Mass-Spring System

    Homework Statement A mass "m" is attached to the free end of a light vertical spring (unstretched length L) of spring contant "k" and suspended from a ceiling. The spring streches by Delta L under the load and comes to equilibrium at a height "h" above the ground level (y=0). The mass is...
  39. A

    Simple harmonic motion problem involving matrices

    Homework Statement 2 equal masses are joined together by a spring of stiffness k. each of the masses is then connected to a wall with an identical spring. derive the equations of motion in matrix form. (a diagam has 2 masses with x1 on top of the first mass and x2 on top of the second.)...
  40. P

    Simple Harmonic Motion of a mass hanger

    Homework Statement A 50 g mass hanger hangs moitionless from a partially stretched spring. When a 91 gram mass is added to the hanger, the spring stretch increases by 7 cm. What is the spring constant of the spring (in N/m)? (Assume g = 9.79 m/s2.) Homework Equations F=k(delta)L-mg...
  41. S

    Simple harmonic motion equation form

    Homework Statement what is the form of the equation of motion for the SHM of a mass suspended on a spring when the mass is initially (a)released 10 cm above the equilibrium position; (b) given an upward push from the equilibrium position, so that it undergoes a maximum displacement of 8cm; (c)...
  42. M

    Displacment in simple harmonic motion after periodic time

    i just studied S.H.M and i am wondering is the displacement equals the amplitude or zero after the periodic time? because when i thought it equals zero at first because the periodic time is time required for the object to make acomplete oscillation and return to it's starting point right? but...
  43. H

    Simple Harmonic Motion: Pendulum of Clock Replaced by Spring-Mass

    Homework Statement The pendulum of a clock is replaced by a spring-mass system with the spring having spring constant 0.1 N/m. What mass should be attached to the spring? Homework Equations T=2 pi (m/k)1/2 The Attempt at a Solution 1 = 2 pi (m/0.1)1/2 1 = 4 pi2 m/0.1...
  44. W

    Simple Harmonic Motion Discrepancy

    Homework Statement A body oscillates with simple harmonic motion along the x-axis. Its displacement varies with time according to the equation x = 5 sin(πt + π/3) meters. The acceleration in m/s2 of the body at t = 1 second is approximately Homework Equations The harmonic motion ones I...
  45. T

    Simple Harmonic Motion - oscillation b/w 2 stretched springs

    Homework Statement A mass M is connected between 2 stretched springs, as shown. The equilibrium length of each spring is L, they are stretched to twice this length when m is in equilibrium. Consider the oscillations in the + and - x direction as shown in the figure...
  46. Q

    Simple Harmonic motion of the following oscillations

    Homework Statement The figure below shows the x(t) curves for three experiments involving a particular spring-box system oscillating in SHM. (a) Rank the curves according to the system's angular frequency, greatest first (use only the symbols > or =, for example 1>2=3). (b) Rank the curves...
  47. C

    Understanding Simple Harmonic Motion: Solving the Second Order ODE

    The equation of simple harmonic motion is given as (d2x)/(dt2)+xk^2=0 Could someone show me HOW we arrive at the general solution to this second order ODE
  48. N

    Solving Simple Harmonic Motion: Algebraic Trick Needed?

    Hello I'm trying to find a formula for a Simple Harmonic Oscillator. After some algebra I've got it down to; \ddot{r}-A*\sqrt{r^{2}-B^{2} } = 0 where A and B are constants. I'm trying to get it down to be in the form of \ddot{r} + C*r = 0 I am feeling like a dummy cause it...
  49. P

    Energy and Simple Harmonic Motion of block

    Homework Statement A 3.2-kg block is hanging stationary from the end of a vertical spring that is attached to the ceiling. The elastic potential energy of this spring/mass system is 1.8J. What is the elastic potential energy of the system when the 3.2-kg block is replaced by a 5.0-kg block...
  50. P

    Simple Harmonic Motion and Reference Circle

    Thank you in advance! Homework Statement A 3.0-kg block is between two horizontal springs. Neither spring is trained when the block is at the position labeled x=0 m in the drawing. The block is then displaced a distance of 0.070m from the position where x=0m and is released from rest. (a) What...
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