A car traveling at 80 kilmeters per hour is passed by a seco

A car traveling at 80 kilmeters 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.

Solution

for units lets use km, hr
remember distance=velocity * time (60 miles=60 mph * 1 hr)
distance given as 500 meters * 1 km/1000m = .5 km
time given as 30 sec *1/60sec/min *1/60min/hr=.0083 hr
Let x = speed of faster car
d=vt
.5=(x-80) * .0083
divide both sides by .0083, and then add 80
.5/.0083+80=x
60.24 +80=x
140.24 =x ANSWER