/*! 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 79 SHM of a Butcher's Scale. A spri... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

SHM of a Butcher's Scale. A spring of negligible mass and force constant \(k=400 \mathrm{~N} / \mathrm{m}\) is hung vertically, and a \(0.200 \mathrm{~kg}\) pan is suspended from its lower end. A butcher drops a \(2.2 \mathrm{~kg}\) steak onto the pan from a height of \(0.40 \mathrm{~m} .\) The steak makes a totally inelastic collision with the pan and sets the system into vertical SHM. What are (a) the speed of the pan and steak immediately after the collision; (b) the amplitude of the subsequent motion; (c) the period of that motion?

Short Answer

Expert verified
The speed of the pan and steak immediately after the collision is 0.39 m/s, the amplitude of the subsequent motion is 0.1975 m, and the period of that motion is 1.178 s.

Step by step solution

01

Calculate the speed after collision

Use the principle of conservation of linear momentum for total inelastic collisions. The initial momentum of the steak and pan is equal to their final momentum. So, \(m_{steak} \cdot v_{steak} + m_{pan} \cdot v_{pan} = (m_{steak} + m_{pan}) \cdot v_f\), where \(v_{steak} = \sqrt{2gh}\) is the initial velocity of the steak, \(v_{pan} = 0\) is the initial velocity of the pan, \(v_f\) is the final velocity.
02

Calculate the amplitude of the subsequent motion

The energy is conserved in the entire process, which implies that the kinetic energy of the steak just after the collision is equal to the potential energy of the steak when it is at an amplitude. Thus the equation becomes \(\frac{1}{2} \cdot (m_{steak} + m_{pan}) \cdot v_f^2 = \frac{1}{2} \cdot k \cdot x_{max}^2\), where \(x_{max}\) is the amplitude of the simple harmonic motion.
03

Calculate the period of that motion

The period of motion \(T\) for a vertical spring is given by \(T = 2 \pi \sqrt{\frac{m}{k}}\), where m is the total mass, which is the sum of the mass of the steak and the pan.

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.

Conservation of Linear Momentum
In physics, the principle of conservation of linear momentum states that if no external forces are acting on a system, the total linear momentum of the system remains constant. This rule is pivotal in analyzing collisions and interactions between objects. When the butcher drops the steak onto the pan, an inelastic collision occurs between the steak and the pan. During this collision, the steak and pan move together after impact, and hence, the system's total momentum just before and just after the collision must be equal.

Let's make this practical: assume the steak is falling at a certain velocity when it hits the pan. Before the collision, the pan is stationary, so its momentum is zero. The steak has a momentum equal to its mass times the velocity acquired from the fall. After the collision, both the steak and pan move with a common velocity, which can be found using the formula \(m_{steak} \cdot v_{steak} = (m_{steak} + m_{pan}) \cdot v_f\). This concept ensures that we can determine the final velocity of the steak-pan system by applying the conservation of linear momentum.
Inelastic Collisions
An inelastic collision is one in which the colliding objects stick together after the impact, and some of the kinetic energy is converted into other forms of energy, such as heat or sound, rather than being conserved. However, even though kinetic energy is not conserved, the total energy of the system is conserved. This type of collision differs from elastic collisions, where both momentum and kinetic energy are conserved.

In the steak and pan scenario, when the butcher drops the steak onto the pan and they stick together, the collision is totally inelastic. As a result, after the collision, the objects move with a single velocity, and some kinetic energy is converted into other forms of energy, possibly deforming the steak or pan upon impact. While kinetic energy changes, the momentum before and after the collision does not, allowing calculations involving the final velocity of the mass-spring system.
Energy Conservation
The principle of energy conservation is a fundamental concept in physics, stating that the total energy in an isolated system remains constant over time. This principle applies to the steak and pan system, where, after the inelastic collision, the energy involved takes on different forms: from gravitational potential energy to kinetic energy and eventually to elastic potential energy of the spring in simple harmonic motion.

To tie this to the problem at hand, just after the collision, the steak and pan have maximum kinetic energy, which will be entirely converted to the spring's potential energy at the peak of the motion, which is the amplitude \(x_{max}\). Therefore, we can equate the kinetic energy right after the collision to the spring potential energy at maximum compression or extension to determine \(x_{max}\). The equation \(\frac{1}{2} \cdot (m_{steak} + m_{pan}) \cdot v_f^2 = \frac{1}{2} \cdot k \cdot x_{max}^2\) illustrates this transformation of energy within the system.
Period of Motion
The period of motion, usually denoted by \(T\), is the time it takes for one complete cycle of simple harmonic motion (SHM). For a system consisting of a mass and spring, the period is determined by the mass of the object and the force constant of the spring and is unhindered by the amplitude of the motion.

Given the mass-spring system of the steak and pan, the total mass \(m\) includes both the mass of the pan and the steak. The force constant \(k\) is a measure of the spring's stiffness. The formula to calculate the period is \(T = 2 \pi \sqrt{\frac{m}{k}}\). By plugging in the total mass of the steak-pan system and the spring's force constant, we can precisely calculate the period of their resulting oscillatory motion. This value will be the time it takes for the steak and pan to oscillate up and down once fully, regardless of how high they rise after the collision.

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

\(\mathrm{A}\) mass is oscillating with amplitude \(A\) at the end of a spring. How far (in terms of \(A\) ) is this mass from the equilibrium position of the spring when the elastic potential energy equals the kinetic energy?

A thrill-seeking cat with mass \(4.00 \mathrm{~kg}\) is attached by a harness to an ideal spring of negligible mass and oscillates vertically in SHM. The amplitude is \(0.050 \mathrm{~m},\) and at the highest point of the motion the spring has its natural unstretched length. Calculate the elastic potential energy of the spring (take it to be zero for the unstretched spring), the kinetic energy of the cat, the gravitational potential energy of the system relative to the lowest point of the motion, and the sum of these three energies when the cat is (a) at its highest point; (b) at its lowest point; (c) at its equilibrium position.

BIO (a) Music. When a person sings, his or her vocal cords vibrate in a repetitive pattern that has the same frequency as the note that is sung. If someone sings the note \(\mathrm{B}\) flat, which has a frequency of \(466 \mathrm{~Hz}\), how much time does it take the person's vocal cords to vibrate through one complete cycle, and what is the angular frequency of the cords? (b) Hearing. When sound waves strike the eardrum, this membrane vibrates with the same frequency as the sound. The highest pitch that young humans can hear has a period of \(50.0 \mu \mathrm{s}\). What are the frequency and angular frequency of the vibrating eardrum for this sound? (c) Vision. When light having vibrations with angular frequency ranging from \(2.7 \times 10^{15} \mathrm{rad} / \mathrm{s}\) to \(4.7 \times 10^{15} \mathrm{rad} / \mathrm{s}\) strikes the retina of the eye, it stimulates the receptor cells there and is perceived as visible light. What are the limits of the period and frequency of this light? (d) Ultrasound. High-frequency sound waves (ultrasound) are used to probe the interior of the body, much as x rays do. To detect small objects such as tumors, a frequency of around \(5.0 \mathrm{MHz}\) is used. What are the period and angular frequency of the molecular vibrations caused by this pulse of sound?

A \(5.00 \mathrm{~kg}\) partridge is suspended from a pear tree by an ideal spring of negligible mass. When the partridge is pulled down \(0.100 \mathrm{~m}\) below its equilibrium position and released, it vibrates with a period of \(4.20 \mathrm{~s}\). (a) What is its speed as it passes through the equilibrium position? (b) What is its acceleration when it is \(0.050 \mathrm{~m}\) above the equilibrium position? (c) When it is moving upward, how much time is required for it to move from a point \(0.050 \mathrm{~m}\) below its equilibrium position to a point \(0.050 \mathrm{~m}\) above it? (d) The motion of the partridge is stopped, and then it is removed from the spring. How much does the spring shorten?

Four passengers with combined mass \(250 \mathrm{~kg}\) compress the springs of a car with worn-out shock absorbers by \(4.00 \mathrm{~cm}\) when they get in. Model the car and passengers as a single object on a single ideal spring. If the loaded car has a period of vibration of \(1.92 \mathrm{~s}\), what is the period of vibration of the empty car?

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.