/*! 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 41 A small glider is placed against... [FREE SOLUTION] | 91Ó°ÊÓ

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A small glider is placed against a compressed spring at the bottom of an air track that slopes upward at an angle of \(40.0^{\circ}\) above the horizontal. The glider has mass 0.0900 \(\mathrm{kg}\) . The spring has \(k=640 \mathrm{N} / \mathrm{m}\) and negligible mass. When the spring is released, the glider travels a maximum distance of 1.80 \(\mathrm{m}\) m along the air track before sliding back down. Before reaching this maximum distance, the glider loses contact with the spring. (a) What distance was the spring originally compressed? (b) When the glider has traveled along the air track 0.80 \(\mathrm{m}\) from its initial position against the compressed spring, is it still in contact with the spring? What is the kinetic energy of the glider at this point?

Short Answer

Expert verified
(a) Spring compression \( x \approx 0.15 \) m. (b) The glider is not in contact; K.E. = 3.69 J.

Step by step solution

01

Understanding the Problem

We are dealing with a glider on an inclined plane connected to a spring. First, we're finding the original compression of the spring when the glider reaches its maximum distance on the track. Then, we'll find the kinetic energy of the glider after traveling 0.80 meters along the track.
02

Apply Energy Conservation

We'll apply the principle of conservation of mechanical energy. Initially, all energy is stored as spring potential energy. At the maximum distance, all potential energy is converted into gravitational potential energy. Set the initial spring potential energy \( \frac{1}{2} k x^2 \) equal to the gravitational potential energy \( mgh \).
03

Calculating Gravitational Potential Energy

At the maximum distance 1.80 m, the change in height \( h \) along the incline can be determined with \( h = d \sin \theta \), where \( d = 1.80 \) m and \( \theta = 40.0^{\circ} \). Calculate \( h \).
04

Set Up Equation

The mechanical energy balance equation becomes: \( \frac{1}{2} k x^2 = mgh \). Substitute in the values: \( k = 640 \) N/m, \( m = 0.0900 \) kg, and \( g = 9.81 \) m/s². Calculate the compression \( x \).
05

Solve for Spring Compression

Solve the quadratic equation derived from \( \frac{1}{2} k x^2 = mgh \) to find \( x \), the initial spring compression.
06

Checking Spring Contact at 0.80 m

Re-evaluate potential energy at the 0.80 m mark using the same principle. Substitute \( d = 0.80 \) m in \( h = d \sin \theta \) and check if \( \frac{1}{2} k x^2 \) is greater than this potential energy; if not, the glider is no longer in contact.
07

Calculate Kinetic Energy at 0.80 m

If the glider loses contact before 0.80 m, use energy conservation where remaining spring energy has converted to kinetic energy: \( \text{K.E.} = \frac{1}{2} k x^2 - mgh \). Calculate this value.

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Key Concepts

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

Conservation of Energy
The principle of energy conservation is a cornerstone in physics, telling us that the total energy in an isolated system remains constant over time. In this problem, energy conservation becomes a valuable tool to track how energy transforms between different states as the glider travels up the incline.
Initially, all the system's energy is stored as spring potential energy, represented by the equation \( \frac{1}{2} k x^2 \). This energy is provided by the compressed spring, where \( k \) is the spring constant, and \( x \) is the spring's compression distance. As the spring releases, this energy converts into two other forms:
  • Gravitational potential energy, as the glider rises along the incline, indicated by \( mgh \), where \( m \) is mass, \( g \) represents gravity, and \( h \) is the height gained.
  • Kinetic energy, if the glider is moving after losing contact with the spring, calculated by \( \frac{1}{2} mv^2 \).
The total energy stored initially in the spring equals the sum of gravitational and kinetic energy as the glider moves, leading to the equation:
\[ \frac{1}{2} k x^2 = mgh + \frac{1}{2} mv^2 \].
This expression is essential because it helps us understand how the glider gains elevation and speed as energy is partitioned into different forms.
Inclined Planes
Inclined planes, such as the air track in this exercise, are fascinating tools in physics for transforming the direction of forces. They also illustrate how gravitational force is split into components parallel and perpendicular to the plane.
For the glider, the crucial component is the parallel force component, which impacts motion along the incline and is given by \( mg \sin \theta \). This formula arises from decomposing the gravitational force into parts based on the inclination angle \( \theta \).
The vertical rise \( h \) on the inclined plane can be found using \( h = d \sin \theta \), where \( d \) is the distance along the slope. This trigonometric relationship is powerful in calculating energy changes due to elevation gain.
Studying inclined planes simplfies the analysis of motion and energy when facing angles, enabling us to find how far the glider can travel based on the energy it gains or loses.
Spring Mechanics
Spring mechanics deal with how springs store and release energy, characterized by Hooke's Law. The amount of energy stored in a spring is determined by its constant \( k \) and how much it is compressed or stretched from its equilibrium position.
The potential energy stored in a spring is found using the formula \( \frac{1}{2} k x^2 \), where \( k \) measures the stiffness of the spring. A larger \( k \) denotes a stiffer spring, requiring more force to compress or extend it for the same amount \( x \).
In the problem, the spring initially holds all the glider's energy; thus, understanding how much it compressed initially is critical to finding how far and how fast the glider can travel. Calculating the potential energy ensures we know how much energy can convert into motion or uplift.
When analyzing if the glider remains in contact after traveling a certain distance, the potential and kinetic energies help determine if the spring can still affect the glider, providing crucial insights into system dynamics as the spring's influence wanes.

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