Question

Car A is traveling north on a straight highway and car B is traveling west on a different straight highway. Each car is approaching the intersection of these highways. At a certain moment, car A is 0.3 km from the intersection and traveling at 90 km/h while car B is 0.4 km from the intersection and traveling at 80 km/h. How fast is the distance between the cars changing at that moment?

Answer 1

Car A is 1.8-1.2= 0.6 times faster than car B

So the distance between them is changing 0.6 times faster.

Step-by-step explanation:

Car A is traveling north at 90km/hr and 0.3 km away from intersection point.

Car b is traveling west at 80km/hr and 0.4 km away from the intersection point.

The time it will take to get to intersection point by those two cars is how fast it is changing.

For car A

Time = distance/speed

Time = 0.3/90

Time = 3.333*10^-3

Time = 3.333*10^-3 hrs

Converting to seconds

(3.333*10^-3)*360= 1.199998

Approximately 1.2 seconds

For car B

Time = distance/time

Time= 0.4/80

Time = 5*10^-3

Time= 5*10^-3 hrs

Converting to seconds

(5*10^-3)*360= 1.8 seconds

Comparing the two times,

Car A is 1.8-1.2= 0.6 times faster than car B