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Chapter 2: Q22. (page 44)

A car slows down from 28 m/s to rest at a distance of 88 m. What is its acceleration, assumed constant?

Short Answer

Expert verified

The acceleration of the car is -4.45 ms2.

Step by step solution

01

Step 1. Relation between the initial velocity, final velocity, distance, and acceleration

Distance and displacement are used to measure the same quantities and have the same units, but displacement is defined as the shortest distance between two points.

Given data.

The initial velocity is vo = 28 ms.

The final velocity is v=0as comes to rest.

The distance is x - xo = 88 m.

Assumption.

Let the acceleration be a.

Now, by the third equation of motion,

role="math" localid="1642829767845" v2 = vo2 + 2ax - xo…(i).

02

Step 2. Calculation of the acceleration

Now, using equation (i),

v2 = vo2 + 2ax - xo02 = 28 ms2 + 2a × 88 ma = - 4.45 ms2

Therefore, the acceleration of the car is - 4.45 ms2.

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Most popular questions from this chapter

A person jumps off a diving board 4.0 m above the water’s surface into a deep pool. The person’s downward motion stops 2.0 m below the surface of the water. Estimate the average deceleration of the person while under the water.

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FIGURE 2-45Problem 62

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FIGURE 2-49 Problem 73.

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Figure 2-44Problems 57,58 and 59
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