Domanda del libro di testo
How much work must you do to push a 10 kg block of steel across a steel table at a steady speed of 1.0m/s for 3.0 s? What is your power output while doing so?
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Ch 09: Work and Kinetic Energy
Knight Calc5th EditionPhysics for Scientists and EngineersISBN: 9780137344796
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TOC.tableOfContents
- Ch 01: Concepts of Motion35
- Ch 02: Kinematics in One Dimension75
- Ch 03: Vectors and Coordinate Systems58
- Ch 04: Kinematics in Two Dimensions60
- Ch 05: Force and Motion23
- Ch 06: Dynamics I: Motion Along a Line53
- Ch 07: Newton's Third Law27
- Ch 08: Dynamics II: Motion in a Plane52
- Ch 09: Work and Kinetic Energy56
- Ch 10: Interactions and Potential Energy50
- Ch 11: Impulse and Momentum56
- Ch 12: Rotation of a Rigid Body71
- Ch 13: Newton's Theory of Gravity52
- Ch 14: Fluids and Elasticity44
- Ch 15: Oscillations55
- Ch 16: Traveling Waves37
- Ch 17: Superposition39
- Ch 18: A Macroscopic Description of Matter53
- Ch 19: Work, Heat, and the First Law of Thermodynamics60
- Ch 20: The Micro/Macro Connection53
- Ch 21: Heat Engines and Refrigerators34
- Ch 22: Electric Charges and Forces40
- Ch 23: The Electric Field39
- Ch 24: Gauss' Law32
- Ch 25: The Electric Potential63
- Ch 26: Potential and Field57
- Ch 27: Current and Resistance42
- Ch 28: Fundamentals of Circuits39
- Ch 29: The Magnetic Field47
- Ch 30: Electromagnetic Induction60
- Ch 31: Electromagnetic Fields and Waves32
- Ch 32: AC Circuits63
- Ch 33: Wave Optics32
- Ch 34: Ray Optics57
- Ch 35: Optical Instruments30
- Ch 36: Special Relativity38
- Ch 37: The Foundations of Modern Physics25
- Ch 38: Quantization49
- Ch 39: Wave Functions and Uncertainty31
- Ch 40: One-Dimensional Quantum Mechanics35
- Ch 41: Atomic Physics18
- Ch 42: Nuclear Physics27
Knight Calc5th EditionPhysics for Scientists and EngineersISBN: 9780137344796Non è quello che usi tu?Cambia libro di testo
Capitolo 9, Problema 33
A baggage handler throws a 15 kg suitcase along the floor of an airplane luggage compartment with a speed of 1.2 m/s. The suitcase slides 2.0 m before stopping. Use work and energy to find the suitcase's coefficient of kinetic friction on the floor.
Guida verificata passo dopo passo1
Step 1: Identify the key concepts involved in the problem. This problem involves the work-energy principle and the relationship between frictional force and the coefficient of kinetic friction. The suitcase's initial kinetic energy is converted into work done against friction as it slides to a stop.
Step 2: Write the expression for the initial kinetic energy of the suitcase. The kinetic energy is given by \( KE = \frac{1}{2} m v^2 \), where \( m \) is the mass of the suitcase (15 kg) and \( v \) is its initial velocity (1.2 m/s).
Step 3: Relate the work done by friction to the kinetic energy. The work done by friction is \( W = F_{friction} \cdot d \), where \( F_{friction} = \mu_k \cdot m \cdot g \), \( \mu_k \) is the coefficient of kinetic friction, \( m \) is the mass, \( g \) is the acceleration due to gravity (9.8 m/s²), and \( d \) is the distance the suitcase slides (2.0 m).
Step 4: Set the work done by friction equal to the initial kinetic energy. Using the work-energy principle, \( \frac{1}{2} m v^2 = \mu_k \cdot m \cdot g \cdot d \). Notice that the mass \( m \) cancels out from both sides of the equation.
Step 5: Solve for \( \mu_k \), the coefficient of kinetic friction. Rearrange the equation to isolate \( \mu_k \): \( \mu_k = \frac{\frac{1}{2} v^2}{g \cdot d} \). Substitute the known values for \( v \), \( g \), and \( d \) to calculate \( \mu_k \).
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8mConcetti chiave
Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.
Work-Energy Principle
The Work-Energy Principle states that the work done on an object is equal to the change in its kinetic energy. In this scenario, the suitcase starts with a certain kinetic energy due to its speed and comes to a stop, meaning its final kinetic energy is zero. The work done by friction is what causes this change in energy, allowing us to relate the distance slid to the force of friction.
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Percorso guidato
04:10
The Work-Energy Theorem
Kinetic Friction
Kinetic friction is the force that opposes the motion of two surfaces sliding past each other. It is proportional to the normal force and is characterized by the coefficient of kinetic friction (μk). This coefficient quantifies how much frictional force acts on the suitcase as it slides, and it can be calculated using the relationship between the frictional force, the normal force, and the acceleration due to friction.
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Percorso guidato
06:18Kinetic Friction Problems
Frictional Force and Normal Force
The frictional force acting on an object is given by the equation F_friction = μk * N, where N is the normal force. For a suitcase on a flat surface, the normal force equals the weight of the suitcase (mass times gravitational acceleration). Understanding this relationship is crucial for calculating the coefficient of kinetic friction, as it directly influences the deceleration of the suitcase as it slides to a stop.
Video consigliato:
Percorso guidato
08:17The Normal Force
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