SOLUTION: Math Question Simple it is ? John of height 1.2m is going away from the lamp post at speed of 1.5m/s. If the lamp post is 3.9 m above the ground then the length of his shadow aft

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Question 804226: Math Question Simple it is ?
John of height 1.2m is going away from the lamp post at speed of 1.5m/s.
If the lamp post is 3.9 m above the ground then the length of his shadow after 3 seconds is ?

Answer by solver91311(24713)   (Show Source): You can put this solution on YOUR website!


It would be easy, relatively speaking, had you bothered to mention how far away from the pole he was when he started walking. Since you didn't, I have to guess that he was right next to the lamppost when he started moving.

At 1.5 m/sec, in 3 sec, he moves 4.5 meters. So after 3 seconds, you have two similar triangles, one that has a leg of 1.2 meters (his height) and another leg of meters (the length of his shadow and ultimately the answer to this problem). The other triangle has a leg that measures 3.9 meters and the other leg is the 4.5 meters he has moved away PLUS the meter length of his shadow.

Corresponding sides of similar triangles are proportional, so:



Solve for

John

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