/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 43 John drives \(16 \mathrm{km}\) d... [FREE SOLUTION] | 91Ó°ÊÓ

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John drives \(16 \mathrm{km}\) directly west from Orion to Chester at a speed of \(90 \mathrm{km} / \mathrm{h},\) then directly south for \(8.0 \mathrm{km}\) to Seiling at a speed of \(80 \mathrm{km} / \mathrm{h}\), then finally $34 \mathrm{km}\( southeast to Oakwood at a speed of \)100 \mathrm{km} / \mathrm{h}$. Assume he travels at constant velocity during each of the three segments. (a) What was the change in velocity during this trip? [Hint: Do not assume he starts from rest and stops at the end.] (b) What was the average acceleration during this trip?

Short Answer

Expert verified
Answer: To find the change in velocity and average acceleration, you'll need to follow the steps outlined in the solution and plug in the given values for each step. Specifically: 1. Calculate the velocity vector for each segment separately. 2. Determine the initial and final velocity vectors. 3. Calculate the change in velocity. 4. Determine the time spent in each segment. 5. Calculate the total time and average acceleration. Once you've completed these calculations, you'll have the change in velocity and the average acceleration during John's trip.

Step by step solution

01

Calculate the velocity for each segment

First, we need to determine the velocity vector for each segment of the trip using given speed and direction. Segment west, from Orion to Chester: Speed: \(90\,\mathrm{km/h}\) Direction: west (\(0^\circ\)) Velocity vector: \(\vec{v}_1 = 90\,\mathrm{km/h} * \cos(0) \, \mathrm{\hat{i}} + 90\,\mathrm{km/h} * \sin(0)\, \mathrm{\hat{j}}\) Segment south, from Chester to Seiling: Speed: \(80\,\mathrm{km/h}\) Direction: south (\(270^\circ\)) Velocity vector: \(\vec{v}_2 = 80\,\mathrm{km/h} * \cos(270) \, \mathrm{\hat{i}} + 80\,\mathrm{km/h} * \sin(270) \, \mathrm{\hat{j}}\) Segment southeast, from Seiling to Oakwood: Speed: \(100\,\mathrm{km/h}\) Direction: southeast (\(135^\circ\)) Velocity vector: \(\vec{v}_3 = 100\,\mathrm{km/h} * \cos(135) \, \mathrm{\hat{i}} + 100\,\mathrm{km/h} * \sin(135) \, \mathrm{\hat{j}}\)
02

Calculate the initial and final velocity vectors

The initial velocity vector is the velocity vector of the first segment: \(\vec{v}_i = \vec{v}_1\) The final velocity vector is the velocity vector of the last segment: \(\vec{v}_f = \vec{v}_3\)
03

Determine the change in velocity

The change in velocity can be calculated as the difference between the final and initial velocity vectors: \(\Delta \vec{v} = \vec{v}_f - \vec{v}_i\)
04

Calculate the time for each segment

We need to determine the time spent during each segment of the trip to calculate the total time. Time spent in segment 1 (west): \(t_1 = \frac{16 \mathrm{km}}{90\,\mathrm{km/h}}\) Time spent in segment 2 (south): \(t_2 = \frac{8 \mathrm{km}}{80\,\mathrm{km/h}}\) Time spent in segment 3 (southeast): \(t_3 = \frac{34 \mathrm{km}}{100\,\mathrm{km/h}}\)
05

Calculate the total time and average acceleration

The total time can be calculated by adding the time for each segment: \(t_{total} = t_1 + t_2 + t_3\) Finally, we can calculate the average acceleration using the change in velocity and the total time: \(\vec{a}_{avg} = \frac{\Delta \vec{v}}{t_{total}}\) Now you can plug in the numbers and compute the change in velocity and average acceleration for the given problem.

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