Skip to main content
Ch. 8 - Integration Techniques
Briggs - Calculus: Early Transcendentals 3rd Edition
Briggs3rd EditionCalculus: Early TranscendentalsISBN: 9780136847243당신이 사용하는 게 아니라요?교과서 변경
8장, 문제 8.R.110

110. Comparing distances Suppose two cars started at the same time and place (t = 0 and s = 0). The velocity of car A (in mi/hr) is given by
u(t) = 40 / (t + 1) and the velocity of car B (in mi/hr) is given by v(t) = 40 * e^(-t/2).
b. After t = 3 hr, which car has traveled farther?

검증된 단계별 안내
1
Recall that the distance traveled by a car from time \(t=0\) to \(t=3\) is the integral of its velocity function over that interval. So, for each car, we need to compute \(\int_0^3 u(t) \, dt\) and \(\int_0^3 v(t) \, dt\) respectively.
Set up the integral for car A's distance: \(\int_0^3 \frac{40}{t+1} \, dt\). This integral involves a rational function and can be solved using the natural logarithm function.
Set up the integral for car B's distance: \(\int_0^3 40 e^{-t/2} \, dt\). This integral involves an exponential function and can be solved using the formula for integrating exponentials.
Evaluate both integrals separately by applying the appropriate integration techniques: for car A, use the substitution \(u = t+1\); for car B, use the standard integral \(\int e^{kt} dt = \frac{1}{k} e^{kt} + C\).
After finding the expressions for the distances traveled by both cars at \(t=3\), compare the two values to determine which car has traveled farther.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
4m
도움이 되었나요?

주요 개념

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

Velocity and Displacement Relationship

Velocity is the rate of change of displacement with respect to time. To find the total distance traveled by an object over a time interval, you integrate its velocity function over that interval. This integral gives the displacement, which in this context represents the distance traveled by each car.
추천 영상:
가이드 코스
06:29
Derivatives Applied To Velocity

Definite Integration

Definite integration calculates the accumulated quantity, such as distance, over a specific interval. Here, integrating the velocity functions from t = 0 to t = 3 hours will yield the total distance each car has traveled. Understanding how to set up and evaluate these integrals is essential.
추천 영상:
가이드 코스
05:43
Definition of the Definite Integral

Exponential and Rational Functions

The velocity functions involve different types of functions: car A's velocity is a rational function, and car B's velocity is an exponential decay function. Recognizing their forms helps in choosing appropriate integration techniques and understanding how their speeds change over time.
추천 영상:
5:46
Graphs of Exponential Functions