Answer:
135° (degrees)
Explanation:
The Earth rotates 360° in about 24 h
How many degrees in 1 hour
[tex]360^{\circ}=24\ h\\\Rightarrow 1\ h=\frac{360}{24}\\\Rightarrow 1\ h=15^{\circ}[/tex]
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
[tex]9\ h=9\times 15^{\circ}=135^{\circ}\\\Rightarrow 9\ h=135^{\circ}[/tex]
So, a person would have to travel 135 degrees in order to reset their watch by 9 hours.