8 - University Physics with Modern Physics

Question

While driving in an exotic foreign land, you see a speed limit sign that reads 180,000 furlongs per fortnight. How many miles per hour is this? (One furlong is 1/8 mile, and a fortnight is 14 days. A furlong originally referred to the length of a plowed furrow.)

Step-by-Step Solution

Answer

The speed is 67 miles/hour

Conversion of furlong and fornight

Furlong and fornight are the units used in olded days to measure the distance and the time travelled by a person respectively.

Given data:

The speed limit is v=180,000 furlongs per fortnight.

The given conversion is,

 $$\begin{gathered} 1 furlong=\frac{1}{8}mile \\ 1 fortnight=14 days \end{gathered}$$

Conversion into mile/ hour

The conversion of velocity is shown below,

 $$\begin{gathered} v=180000 furlongs per fortnight \\ v=180000\frac{furlongs}{fortnight}\times \frac{1 fortnight}{14 days}\times \frac{1 day}{24 hrs}\times \frac{{\displaystyle \frac{1}{8}}miles}{1 furlong} \\ v=67 miles/hr \end{gathered}$$

 

Therefore, It is concluded that the speed limit is 67 miles/hour.