/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 26 A \(0.150-\mathrm{kg}\) toy is u... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

A \(0.150-\mathrm{kg}\) toy is undergoing SHM on the end of a horizontal spring with force constant \(k=300 \mathrm{N} / \mathrm{m}\) . When the object is 0.0120 \(\mathrm{m}\) from its equilibrium position, it is observed to have a speed of 0.300 \(\mathrm{m} / \mathrm{s}\) . What are (a) the total energy of the object at any point of its motion; (b) the amplitude of the motion; (c) the maximum speed attained by the object during its motion?

Short Answer

Expert verified
(a) 0.02835 J; (b) 0.01375 m; (c) 0.615 m/s.

Step by step solution

01

Determine the Total Energy Using Conservation of Energy

The total mechanical energy (\(E\)) in simple harmonic motion is the sum of its potential and kinetic energies. At any point in SHM, total energy \(E\) is constant and can be expressed as:\[E = K + U \]where \(K\) is the kinetic energy and \(U\) is the potential energy.The kinetic energy is:\[K = \frac{1}{2} m v^2 \]and the potential energy stored in the spring is:\[U = \frac{1}{2} k x^2 \]Substituting the given values \(m = 0.150 \text{ kg}\), \(v = 0.300 \text{ m/s}\), \(k = 300 \text{ N/m}\), and \(x = 0.0120 \text{ m}\):\[K = \frac{1}{2} (0.150) (0.300)^2 = 0.00675 \text{ J}\]\[U = \frac{1}{2} (300) (0.012)^2 = 0.0216 \text{ J}\]Thus, the total energy is:\[E = 0.00675 + 0.0216 = 0.02835 \text{ J}\]
02

Calculate the Amplitude Using Energy Equations

The total energy \(E\) in SHM can also be expressed using the amplitude \(A\) since energy is maximum when displacement is equal to amplitude. Total energy in terms of amplitude is:\[E = \frac{1}{2} k A^2 \]From Step 1, we know \(E = 0.02835 \text{ J}\). Solving for \(A\):\[0.02835 = \frac{1}{2} (300) A^2\]\[A^2 = \frac{0.02835 \times 2}{300}\]\[A^2 = 0.000189\]\[A = \sqrt{0.000189} = 0.01375 \text{ m}\]
03

Determine the Maximum Speed Using Energy Conservation

The maximum speed \(v_{max}\) occurs when the object passes through the equilibrium position, where potential energy is zero and mechanical energy is entirely kinetic:\[E = \frac{1}{2} m v_{max}^2\]With \(E = 0.02835 \text{ J}\) from Step 1:\[0.02835 = \frac{1}{2} (0.150) v_{max}^2\]\[v_{max}^2 = \frac{0.02835 \times 2}{0.150}\]\[v_{max}^2 = 0.378\]\[v_{max} = \sqrt{0.378} = 0.615 \text{ m/s}\]

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Mechanical Energy
In simple harmonic motion (SHM), mechanical energy plays a crucial role. It represents the total energy of the system, combining both kinetic and potential energies. Mechanical energy remains constant as the toy oscillates back and forth on the spring. This constancy is due to the ideal nature of SHM, where no energy is lost to friction or air resistance.

The mechanical energy in SHM, denoted as \(E\), is given by:
  • \(E = K + U\)
where \(K\) is the kinetic energy and \(U\) is the potential energy. This equation tells us that as the toy moves, energy transforms between kinetic and potential forms, but the total stays the same. This principle is essential for understanding how the system behaves dynamically during motion.
Spring Constant
The spring constant, often represented by \(k\), is a measure of a spring's stiffness. In the context of SHM, it's critical because it determines how much force is required to stretch or compress the spring a certain distance. The spring constant is expressed in units of newtons per meter (N/m).

For our exercise, the spring constant is given as 300 N/m. This high value indicates a relatively stiff spring that exerts considerable force, making it responsive to small displacements. Knowing the spring constant is vital for calculating both potential energy and the amplitude of motion. It's also used in the formula:
  • \(U = \frac{1}{2} k x^2\)
where \(x\) is the displacement from the equilibrium position.
Amplitude of Motion
The amplitude of motion, noted as \(A\), is the maximum displacement from the equilibrium position in simple harmonic motion. Amplitude is integral to describing the extent of oscillation. In our problem, we calculate the amplitude using the total mechanical energy, because it's when the spring is fully compressed or extended, and the system has all its energy as potential.

The formula linking energy and amplitude is:
  • \(E = \frac{1}{2} k A^2\)
Solving for \(A\) helps us understand the toy's motion range, showing how far it moves from the center point on each side during its oscillation.
Maximum Speed
In simple harmonic motion, the maximum speed occurs when the object passes through the equilibrium position. At this point, all the system's mechanical energy is kinetic, with potential energy reaching zero.

The calculation of maximum speed, \(v_{max}\), involves rearranging the mechanical energy equation:
  • \(E = \frac{1}{2} m v_{max}^2\)
By substituting known values, maximum speed is determined, which helps us gauge how fast the toy moves as it crosses its equilibrium position. Understanding \(v_{max}\) is essential for predicting dynamic behavior in SHM.
Kinetic Energy
Kinetic energy in the context of SHM refers to the energy associated with an object’s motion. It depends on the mass of the object and its velocity. In our scenario, the kinetic energy changes as the toy moves along the spring.

The formula for kinetic energy \(K\) is:
  • \(K = \frac{1}{2} m v^2\)
As the toy speeds up and slows down through its path, kinetic energy increases when moving towards the equilibrium position and decreases when moving away. Everything converts between kinetic and potential energy while maintaining the total energy constant.
Potential Energy
Potential energy in simple harmonic motion is stored as the spring is compressed or stretched. It represents the energy stored due to the position of the toy relative to its equilibrium point. This energy is pivotal to the cyclic nature of SHM.

The formula for potential energy \(U\) is:
  • \(U = \frac{1}{2} k x^2\)
where \(x\) is the displacement from the equilibrium position. As the toy moves, potential energy reaches its peak when the spring is at either its most compressed or most extended state. Potential energy is minimal when the toy passes through equilibrium, converting to kinetic energy here.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Two identical atoms in a diatomic molecule vibrate as harmonic oscillators. However, their center of mass, midway between them, remains at rest. (a) Show that at any instant, the momenta of the atoms relative to the center of mass are \(\vec{p}\) and \(-\vec{p} .\) (b) Show that the total kinetic energy \(K\) of the two atoms at any instant is the same as that of a single object with mass \(m / 2\) with a momentum of magnitude \(p .\) (Use \(K=p^{2} / 2 m . )\) This result shows why \(m / 2\) should be used in the expression for \(f\) in have masses \(m_{1}\) and \(m_{2},\) show that the result of part (a) still holds and the single object's mass in part (b) is \(m_{1} m_{2} /\left(m_{1}+m_{2}\right) .\) The quantity \(m_{1} m_{2} J\left(m_{1}+m_{2}\right)\) is called the reducedmass of the system.

A large bell is hung from a wooden beam so it can swing back and forth with negligible friction. The center of mass of the bell is 0.60 \(\mathrm{m}\) below the pivot, the bell has mass 34.0 \(\mathrm{kg}\) , and the moment of inertia of the bell about an axis at the pivot is 18.0 \(\mathrm{kg} \cdot \mathrm{m}^{2} .\) The clapper is a small, 1.8-kg mass attached to one end of a slender rod that has length \(L\) and negligible mass. The other end of the rod is attached to the inside of the bell so it can swing freely about the same axis as the bell. What should be the length \(L\) of the clapper rod for the bell to ring silently - that is, for the period of oscillation for the bell to equal that for the clapper?

The point of the needle of a sewing machine moves in SHM along the \(x\) -axis with a frequency of 2.5 \(\mathrm{Hz}\) . At \(t=0\) its position and velocity components are \(+1.1 \mathrm{cm}\) and \(-15 \mathrm{cm} / \mathrm{s}\) , respectively (a) Find the acceleration component of the needle at \(t=0\) . (b) Write equations giving the position, velocity, and accelerationcomponents of the point as a function of time.

The balance wheel of a watch vibrates with an angular amplitude \(\Theta,\) angular frequency \(\omega\) , and phase angle \(\phi=0\) . (a) Find expressions for the angular velocity \(d \theta / d t\) and angular acceleration \(d^{2} \theta / d t^{2}\) as functions of time. (b) Find the balance wheel's angular velocity and angular acceleration when its angular displacement is \(\Theta,\) and when its angular displacement is \(\Theta / 2\) and \(\theta\) is decreasing. (Hint: Sketch a graph of \(\theta\) versus \(t\) )

A machine part is undergoing SHM with a frequency of 5.00 Hz and amplitude 1.80 \(\mathrm{cm} .\) How long does it take the part to go from \(x=0\) to \(x=-1.80 \mathrm{cm} ?\)

See all solutions

Recommended explanations on Physics Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.