posted by Lisa on .
A woman driving a care 14ft long is passing a truck 30 ft long. The truck is traveling at 50 miles per hour. How fast must the woman drive her car so that she can pass the truck completely in 6 seconds?
Assume the truck is standing still, then she must travel a total distance of (14+30)ft in 6 seconds
speed = distance/time = 44 ft/6 sec
44 ft/6 sec = 440 ft/60 sec
= 440 ft/min = 26400 ft/hr
= 5 mi/hr
So she must travel 5 mph faster than the truck, which was going at 50 mph
So she will have to travel 60 mph