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avatar+409 

Peter ran at 4 m/s. Paul started at the same spot 6 sec. later and chased Peter at 7 m/s. Paul needed __ seconds to catch Peter.

 Jan 17, 2019
 #1
avatar+23494 
0

Peter gets a 4 m/s x 6 s = 24 meter head start.....when do their positions equal?

 

24m + 4 m/s * x s   = 7 m/s * x s

24 + 4x = 7x

24 = 3x

x = 8seconds     they will be at the same point    ( 24 m + 4 m/s * 8 sec = 56 meters)

 Jan 17, 2019
edited by ElectricPavlov  Jan 17, 2019
 #2
avatar+111357 
+1

Every second after Paul starts....he  closes the gap between himself and Peter by 7 - 4 =  3m/s

 

So.....6 seconds  after Peter starts, Peter has traveled 6 * 4  =  24 m

 

So....the number of seconds that it will take Paul to catch Peter =   24 /3   =   8 sec

 

 

cool cool cool

 Jan 17, 2019

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