Ch. 02 - Describing Motion: Kinematics in One Dimension

Giancoli Douglas - Physics for Scientists and Engineers 5th edition

Giancoli Douglas5th editionPhysics for Scientists and EngineersISBN: 9780137488179당신이 사용하는 게 아니라요?교과서 변경

Giancoli Douglas 5th edition

Ch. 02 - Describing Motion: Kinematics in One Dimension

문제 14

2장, 문제 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?]

검증된 단계별 안내

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:

t = \frac{d}{v}

, where

d

is the distance and

v

is the speed. For the first segment, substitute

d = 1900

km and

v = 720

km/h. For the second segment, substitute

d = 2700

km and

v = 990

km/h.

Step 3: Add the times from both segments to find the total time for the trip:

t

_total = t₁ + t₂, where

t

₁ is the time for the first segment and

t

₂ is the time for the second segment.

Step 4: Calculate the total distance traveled by adding the distances of both segments:

d

_total = d₁ + d₂, where

d

₁ is 1900 km and

d

₂ is 2700 km.

Step 5: Calculate the average speed of the airplane for the entire trip using the formula:

v

_avg = d_totalt_total, where

d

_total is the total distance and

t

_total is the total time.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

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.

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.

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.