Answer:
The observed temperature was 10º Celsius or 50º Fahrenheit.
Explanation:
The traveler observed that the temperature in Fahrenheit is five times the value of the temperature in Celsius, therefore:

A Fahrenheit temperature relates to a Celsius one by the following expression:

Using the second expression on the first, we can solve for the temperature in Celsius, this is done below:

The observed temperature was 10º Celsius or 50º Fahrenheit.
Answer:
A
Explanation:
because in the moving object there's a certain energy applied
Reflecting telescopes are popular because they are more durable than a refracting telescopes.
There is a difference between these two types of telescopes, reflecting telescopes worked by reflecting light, they are also known as reflector and refracting telescopes worked by refracting light and they are also known as reflactor.
Reflecting telescopes also provides a good focus.