/*! 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 197 A car, moving at a speed of \(50... [FREE SOLUTION] | 91Ó°ÊÓ

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A car, moving at a speed of \(50 \mathrm{~km} / \mathrm{hr}\), can be stopped by brakes after at least \(6 \mathrm{~m}\). If the same car is moving at a speed of \(100 \mathrm{~km} / \mathrm{hr}\), the minimum stopping distance is (A) \(12 \mathrm{~m}\) (B) \(18 \mathrm{~m}\) (C) \(24 \mathrm{~m}\) (D) \(6 \mathrm{~m}\)

Short Answer

Expert verified
The minimum stopping distance at a speed of \(100\mathrm{~km} / \mathrm{hr}\) is approximately \(24\mathrm{~m}\). Therefore, the correct answer is (C) \(24 \mathrm{~m}\).

Step by step solution

01

Setup the initial data and equation

To solve this problem, let's first understand the given data: - At \(50 \mathrm{~km} / \mathrm{hr}\), the car can be stopped in a minimum distance of \(6 \mathrm{~m}\). - We need to find the minimum stopping distance at a speed of \(100\mathrm{~km} / \mathrm{hr}\). Let's assume the stopping distance (\(S\)) is proportional to the square of the speed (\(V^2\)). We want to find if there is a constant (\(k\)) such that this equation is true: \(S = kV^2\)
02

Find k for the initial speed

In order to find the constant \(k\), we need to plug in the initial values: \(6 \mathrm{~m} = k (50\mathrm{~km} / \mathrm{hr})^2\) However, the speed is given in \(\mathrm{km/hr}\), and the stopping distance is given in meters. To avoid any inconsistency, we need to convert the speed from \(\mathrm{km/hr}\) to \(\mathrm{m/s}\). To convert from \(\mathrm{km/hr}\) to \(\mathrm{m/s}\), we can use the following formula: \(1\mathrm{~km} / \mathrm{hr} = \frac{1000}{3600} \mathrm{~m} / \mathrm{s}\) So, the speed at \(50\mathrm{~km} / \mathrm{hr}\) in \(\mathrm{m/s}\) is: \(\frac{50 * 1000}{3600} = 13.88\mathrm{~m/s}\) Now, we can rewrite our initial equation as: \(6 = k(13.88)^2\) To solve for \(k\), we can divide both sides by \((13.88)^2\): \(k = \frac{6}{(13.88)^2} = 0.031\)
03

Determine stopping distance at the higher speed

Now that we have the value of \(k\), we can use it to determine the stopping distance (\(S\)) at the new velocity of \(100\mathrm{~km} / \mathrm{hr}\): First, let's convert the speed to \(\mathrm{m/s}\): \(\frac{100 * 1000}{3600} = 27.77\mathrm{~m/s}\) Now, substitute the known values into our previously derived equation: \(S = 0.031 * (27.77)^2 = 23.96\) The stopping distance at \(100\mathrm{~km} / \mathrm{hr}\) is approximately \(24\mathrm{~m}\).
04

Choose the correct answer

Based on our calculations, the minimum stopping distance at a speed of \(100\mathrm{~km} / \mathrm{hr}\) is approximately \(24\mathrm{~m}\). Therefore, the correct option is: (C) \(24 \mathrm{~m}\)

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