Domanda del libro di testo
A pitcher accelerates a 150 g baseball from rest to 35 m/s. How much work does the pitcher do on the ball?
2737
views
Ch 09: Work and Kinetic Energy
Knight Calc5th EditionPhysics for Scientists and EngineersISBN: 9780137344796
Non è quello che usi tu?Cambia libro di testoScegli un libro di testo diverso
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 1
At what speed does a 1000 kg compact car have the same kinetic energy as a 20,000 kg truck going 25 km/h?
Guida verificata passo dopo passo1
Step 1: Recall the formula for kinetic energy, which is \( KE = \frac{1}{2} m v^2 \), where \( KE \) is the kinetic energy, \( m \) is the mass, and \( v \) is the velocity.
Step 2: Calculate the kinetic energy of the truck using its mass \( m = 20,000 \, \text{kg} \) and velocity \( v = 25 \, \text{km/h} \). First, convert the velocity from \( \text{km/h} \) to \( \text{m/s} \) using the conversion factor \( 1 \, \text{km/h} = \frac{1}{3.6} \, \text{m/s} \).
Step 3: Set the kinetic energy of the car equal to the kinetic energy of the truck. Use \( KE_{\text{car}} = KE_{\text{truck}} \), which translates to \( \frac{1}{2} m_{\text{car}} v_{\text{car}}^2 = \frac{1}{2} m_{\text{truck}} v_{\text{truck}}^2 \). Cancel out the \( \frac{1}{2} \) factor on both sides.
Step 4: Solve for the velocity of the car \( v_{\text{car}} \) by rearranging the equation: \( v_{\text{car}} = \sqrt{\frac{m_{\text{truck}}}{m_{\text{car}}} \cdot v_{\text{truck}}^2} \). Substitute \( m_{\text{truck}} = 20,000 \, \text{kg} \), \( m_{\text{car}} = 1,000 \, \text{kg} \), and \( v_{\text{truck}} \) in \( \text{m/s} \).
Step 5: Perform the square root operation to find the velocity of the car in \( \text{m/s} \). If needed, convert the result back to \( \text{km/h} \) using the factor \( 1 \, \text{m/s} = 3.6 \, \text{km/h} \).
Risposta video verificata per un problema simile:
Questa soluzione video è stata consigliata dai nostri tutor come utile per risolvere questo problema.
Durata del video:
4mConcetti chiave
Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.
Kinetic Energy
Kinetic energy is the energy an object possesses due to its motion, calculated using the formula KE = 1/2 mv², where m is the mass and v is the velocity. This concept is crucial for comparing the energy of different objects in motion, as it directly relates to both their mass and speed.
Video consigliato:
Percorso guidato
06:07
Intro to Rotational Kinetic Energy
Mass and Velocity Relationship
The relationship between mass and velocity is fundamental in understanding how kinetic energy varies with changes in these parameters. For two objects to have the same kinetic energy, adjustments in either mass or velocity must be made, illustrating the inverse relationship between mass and the square of velocity in the kinetic energy formula.
Video consigliato:
Percorso guidato
20:32Mass Spectrometers
Unit Conversion
Unit conversion is essential when dealing with different measurement systems, such as converting kilometers per hour (km/h) to meters per second (m/s). This ensures consistency in calculations, particularly when comparing the kinetic energies of objects with different masses and speeds, as accurate units are necessary for correct results.
Video consigliato:
Percorso guidato
07:46Unit Conversions
Pratica correlata
Domanda del libro di testo
A mother has four times the mass of her young son. Both are running with the same kinetic energy. What is the ratio vson/vmother of their speeds?
2347
views
Domanda del libro di testo
The cable of a crane is lifting a 750 kg girder. The girder increases its speed from 0.25 m/s to 0.75 m/s in a distance of 3.5 m. How much work is done by gravity?
2844
views