Question

We are driving along a highway at a constant speed of 55 miles per hour (mph). you observe a car one half mile behind you. the car is moving fast and zooms past you exactly one minute later. how fast is this car traveling (mph) if its speed is constant?



a. 80

Answer 1

The speed of the car is 84.96 mph

Since the car is 0.5 miles away from you, and crosses you in exactly one min, which means the other car will cover 0.5 miles more in one min than your car

The speed of your car is 55 mph or 0.916 miles per minuter

Therefore the speed of the other car is 0.916+0.5=1.416 miles per minute

Thus the speed of the other car is =1.416*60=84.96 mph