Textbook Question
Every year the Earth travels about 10⁹ km as it orbits the Sun. What is Earth's average speed in km/h?
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Ch. 02 - Describing Motion: Kinematics in One Dimension
Giancoli Douglas5th editionPhysics for Scientists and EngineersISBN: 9780137488179
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Table of contents
- Ch. 01 - Introduction, Measurement, Estimating10
- Ch. 02 - Describing Motion: Kinematics in One Dimension30
- Ch. 03 - Kinematics in Two or Three Dimensions; Vectors15
- Ch. 04 - Dynamics: Newton's Laws of Motion16
- Ch. 05 - Using Newton's Laws: Friction, Circular Motion, Drag Forces22
- Ch. 06 - Gravitation and Newton's Synthesis10
- Ch. 07 - Work and Energy21
- Ch. 08 - Conservation of Energy33
- Ch. 09 - Linear Momentum26
- Ch. 10 - Rotational Motion41
- Ch. 11 - Angular Momentum; General Rotation27
- Ch. 12 - Static Equilibrium; Elasticity and Fracture27
- Ch. 13 - Fluids28
- Ch. 14 - Oscillations14
- Ch. 15 - Wave Motion35
- Ch. 16 - Sound5
- Ch. 17 - Temperature, Thermal Expansion, and the Ideal Gas Law40
- Ch. 18 - Kinetic Theory of Gases18
- Ch. 19 - Heat and the First Law of Thermodynamics31
- Ch. 20 - Second Law of Thermodynamics32
- Ch. 21 - Electric Charge and Electric Field7
- Ch. 23 - Electric Potential20
- Ch. 24 - Capacitance, Dielectrics, Electric Energy, Storage15
- Ch. 25 - Electric Current and Resistance32
- Ch. 26 - DC Circuits22
- Ch. 27 - Magnetism21
- Ch. 28 - Sources of Magnetic Field24
- Ch. 29 - Electromagnetic Induction and Faraday's Law21
- Ch. 30 - Inductance, Electromagnetic Oscillations, and AC Circuits42
- Ch. 31 - Maxwell's Equations and Electromagnetic Waves25
- Ch. 32 - Light: Reflection and Refraction42
- Ch. 33 - Lenses and Optical Instruments21
- Ch. 34 - The Wave Nature of Light: Interference and Polarization26
- Ch. 35 - Diffraction24
- Ch. 36 - The Special Theory of Relativity29
- Ch. 38 - Quantum Mechanics1
- Ch. 40 - Molecules and Solids6
- Ch. 43 - Elementary Particles3
- Ch. 44 - Astrophysics and Cosmology9
Giancoli Douglas5th editionPhysics for Scientists and EngineersISBN: 9780137488179Not the one you use?Change textbook
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Giancoli Douglas 5th editionCh. 02 - Describing Motion: Kinematics in One DimensionProblem 14
Giancoli Douglas 5th editionCh. 02 - Describing Motion: Kinematics in One DimensionProblem 14Chapter 2, Problem 14
An airplane travels 1900 km at a speed of 720 km/h, and then encounters a tailwind that boosts its speed to 990 km/h for the next 2700 km. What was the total time for the trip? What was the average speed of the plane for this trip? [Hint: Does Eq. 2–12d apply?]
Verified step by step guidance1
Step 1: Break the problem into two segments of the trip. The first segment involves the airplane traveling 1900 km at a speed of 720 km/h, and the second segment involves traveling 2700 km at a speed of 990 km/h.
Step 2: Calculate the time taken for each segment of the trip using the formula for time: , where is the distance and is the speed. For the first segment, substitute km and km/h. For the second segment, substitute km and km/h.
Step 3: Add the times from both segments to find the total time for the trip: , where is the time for the first segment and is the time for the second segment.
Step 4: Calculate the total distance traveled by adding the distances of both segments: , where is 1900 km and is 2700 km.
Step 5: Calculate the average speed of the airplane for the entire trip using the formula: , where is the total distance and is the total time.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Speed and Velocity
Speed is a scalar quantity that represents the distance traveled per unit of time, while velocity is a vector quantity that includes both speed and direction. In this problem, understanding the difference between these two concepts is crucial, as the airplane's speed changes due to the tailwind, affecting the overall travel time.
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05:35
Intro to Velocity and Speed
Average Speed
Average speed is defined as the total distance traveled divided by the total time taken. It provides a measure of the overall rate of motion for the entire trip, regardless of variations in speed during different segments. Calculating average speed is essential for answering the second part of the question.
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Guided course
05:44Solving Constant and Average Velocity Problems
Kinematic Equations
Kinematic equations describe the motion of objects under constant acceleration. In this scenario, the airplane travels at two different constant speeds, allowing the use of basic distance, speed, and time relationships to calculate the total time for the trip. The hint regarding Eq. 2–12d suggests that these equations may be relevant for solving the problem.
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08:25Kinematics Equations
Related Practice
Textbook Question
A particle at t₁ = ― 2.0 s is at 𝓍₁ = 5.2 cm and at t₂ = 3.4 s is at 𝓍₂ = 8.5 cm. What is its average velocity over this time interval? Can you calculate its average speed from these data? Why or why not?
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Textbook Question
Sketch the v vs. t graph for the object whose displacement as a function of time is given by Fig. 2–40.
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Textbook Question
A horse trots away from its trainer in a straight line, moving 38 m away in 7.4 s. It then turns abruptly and gallops halfway back in 1.8 s. Calculate its average speed
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Textbook Question
The position of an object along a straight tunnel as a function of time is plotted in Fig. 2–40. What is its average velocity between t = 25.0 s and t = 30.0 s?
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Textbook Question
A bowling ball traveling with constant speed hits the pins at the end of a bowling lane 16.5 m long. The bowler hears the sound of the ball hitting the pins 2.75 s after the ball is released from his hands. What is the speed of the ball, assuming the speed of sound is 340 m/s?
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