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Ch 01: Units, Physical Quantities & Vectors
Chapter 1, Problem 1

How many nanoseconds does it take light to travel 1.00 ft in vacuum? (This result is a useful quantity to remember.)

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1
Identify the speed of light in vacuum, which is approximately $c = 3.00 \times 10^8$ meters per second.
Convert the distance from feet to meters, knowing that 1 foot is approximately 0.3048 meters.
Calculate the distance in meters by multiplying the number of feet by the conversion factor from feet to meters.
Use the formula for time, $t = \frac{d}{v}$, where $d$ is the distance light travels and $v$ is the speed of light.
Substitute the values into the formula and solve for $t$, the time in seconds, then convert the result to nanoseconds by multiplying by $10^9$ (since 1 second equals $10^9$ nanoseconds).

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Speed of Light

The speed of light in a vacuum is approximately 299,792,458 meters per second. This constant is fundamental in physics, as it represents the maximum speed at which information and matter can travel. Understanding this speed is crucial for calculating how long it takes light to cover a specific distance.
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Distance Conversion

To solve the problem, it's essential to convert the distance from feet to meters, as the speed of light is typically expressed in meters per second. One foot is equivalent to 0.3048 meters. Accurate conversion ensures that calculations involving the speed of light yield correct results in the desired units.
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Time Calculation

Time can be calculated using the formula time = distance/speed. By substituting the converted distance in meters and the speed of light in meters per second, one can determine the time it takes for light to travel that distance. This calculation will yield the time in seconds, which can then be converted to nanoseconds for the final answer.
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