<PRE><B>Question 789359</B>
A car traveling at 8o kilometers per hour is passed by a second car going in the same direction at a constant speed. After 30 seconds the two cars are 500 meters apart. Find the speed of the second car.

speed of car II -x mph
speed of car I = 80 kph

Difference = (x-80)

distance between them = 0.5 km
after time (30/3600) hours

d=rt

0.5 = (x-80) * (30/3600)

0.5 * 3600 = 30(x-80)

0.5 * 3600/30 = x-80

60=x-80
x= 80 +60
x= 140 km/h

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