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Ch 02: Motion Along a Straight Line
Young & Freedman Calc - University Physics 14th Edition
Young & Freedman Calc14th EditionUniversity PhysicsISBN: 9780321973610당신이 사용하는 게 아니라요?교과서 변경
2장, 문제 3

You normally drive on the freeway between San Diego and Los Angeles at an average speed of 105105 km/h (6565 mi/h), and the trip takes 11 h and 5050 min. On a Friday afternoon, however, heavy traffic slows you down and you drive the same distance at an average speed of only 7070 km/h (4343 mi/h). How much longer does the trip take?

검증된 단계별 안내
1
First, convert the time of the normal trip from hours and minutes to hours. The trip takes 1 hour and 50 minutes, which is equivalent to 1 + 50/60 hours.
Calculate the distance of the trip using the formula for distance: \( \text{Distance} = \text{Speed} \times \text{Time} \). Use the normal speed of 105 km/h and the converted time from step 1.
Now, calculate the time taken for the trip on Friday afternoon using the formula \( \text{Time} = \frac{\text{Distance}}{\text{Speed}} \). Use the distance calculated in step 2 and the reduced speed of 70 km/h.
Convert the time taken on Friday afternoon from hours to hours and minutes for easier comparison with the normal trip time.
Finally, find the difference in time between the normal trip and the Friday afternoon trip by subtracting the normal trip time from the Friday afternoon trip time. This will give you how much longer the trip takes.

비슷한 문제에 대한 검증된 영상 답변:

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

주요 개념

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

Average Speed

Average speed is defined as the total distance traveled divided by the total time taken to travel that distance. It is a scalar quantity and is typically expressed in units such as kilometers per hour (km/h) or miles per hour (mi/h). Understanding average speed is crucial for calculating travel time over a given distance.
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Distance-Time Relationship

The distance-time relationship is a fundamental concept in kinematics, which states that distance equals speed multiplied by time (d = vt). This relationship allows us to calculate one of these variables if the other two are known, making it essential for solving problems involving travel time and speed.
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Unit Conversion

Unit conversion involves changing a measurement from one unit to another, such as converting time from hours and minutes to just hours. This is important for ensuring consistency in calculations, especially when dealing with different units of speed and time, as seen in this problem where time is given in hours and minutes.
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