[Home] [How to Measure Your Beliefs] [The Man-Made Church] [Miscellaneous]

[Home]>[Miscellaneous]>[8. Astronomy]>[1. Astronomical questions and answers]>[Astronomical question and answer 244]

Previous webpage:           243
To the end of this webpage: End
Next webpage:               245

 

Astronomical question and answer 244

 

Frank L. Preuss

 

How fast is the shadow?

 

A man goes on the pavement in the direction towards the east. Next to him a truck also drives in the direction towards the east. Both have the same speed of 4 km per hour. The sun cast the shadow of the man upon the truck. How fast does the shadow on the truck move?

The shadow on the truck has the speed of 0 km/h.

The truck now stops and the man carries on walking and does not change his speed. How fast does the shadow of the man move?

The shadow of the man moves with a speed of 4 km/h on the truck in the direction towards the east.

The truck now moves again, but with a speed of only 1 km/h. The man carries on walking and also keeps his speed. How fast does his shadow move on the truck?

The speed of the shadow of the man on the truck is 4 km/h minus 1 km/h = 3 km/h, and also again in the direction towards the east.

The name of the man is Mr Newmoon and the truck has the inscription of his company: Planet Earth.

 

This is the end of "Astronomical question and answer 244"
To the German version of this chapter: Astronomische Frage und Antwort 244

 

 

Previous webpage:                 243    
To the beginning of this webpage: Beginning
Next webpage:                     245

[Home]>[Miscellaneous]>[8. Astronomy]>[1. Astronomical questions and answers]>[Astronomical question and answer 244]

[Home] [How to Measure Your Beliefs] [The Man-Made Church] [Miscellaneous]

The address of this webpage is:
http://www.fpreuss.com/en3/en03/en0320/en03244.htm