Question

Until 1883, every city and town in the United States kept its own local time. Today, travelers reset their watches only when the time change equals 1.0 h. How far, on the average, must you travel in degrees of longitude until your watch must be reset by 9 hours? (Hint: Earth rotates 360° in about 24 h.)

Answer 1

Answer:

135° (degrees)

Explanation:

The Earth rotates 360° in about 24 h

How many degrees in 1 hour

$360^{\circ}=24\ h\\\Rightarrow 1\ h=\frac{360}{24}\\\Rightarrow 1\ h=15^{\circ}$

So, in 1 hour the Earth rotates 15 degrees. This means that a person would have to reset their watch by 1 hour after travelling 15 degrees

In 9 hours

$9\ h=9\times 15^{\circ}=135^{\circ}\\\Rightarrow 9\ h=135^{\circ}$

So, a person would have to travel 135 degrees in order to reset their watch by 9 hours.