The Cute Poppy
Heidi, Peter, and the dog Poppy were enjoying the spring season. Peter and Heidi decided to run straight to a tree which is 500 meters away. The three started running at the same time. Peter's velocity was 5.5 m/s and Heidi's velocity was 4 m/s (constant for both of them). Poppy was running with Heidi for the first 5 seconds. Then, Poppy changed his velocity to be 12 m/s and start going toward Peter until he met him. After Poppy met Peter, Poppy stopped for 1 second, before turning back towards Heidi with constant velocity 12 m/s again. After Poppy met Heidi again, Poppy stopped for 1 second and then ran back towards Peter with same constant velocity of 12 m/s. This was repeated over and over.
How long would be the distance between Poppy and Peter after 1 minute?
Give your answer to nearest integer.
The answer is 83.
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1 solution
The problem can be solved by the simple math (but it will be required a many repeating steps and long calculations)
It can be also solved by using the programming languages.
But the easiest way to me is to plot the time / distance diagram for the three characters.
I used A u t o C A D to get accurate measurements. Blue line is Peter movement and Heidi movement is the red line.
Poppy movement (in black) was the tricky one. For the first 5 sec he moved as Heidi then his velocity increased and we can see the change in the slop in the black line, the small horizontal lines are the 1 sec stopping to change the direction each time he meet the other person. then we take the distance between the ends of the blue and the black lines and we can see it is 8 3 m 