Question

3) Car A and B travel in opposite directions. Both cars leave the same location at the same time. Car A is traveling west at a speed of 10 mph more than Car B, which is headed east. Find the speed of Car A if the two cars are 300 miles apart after traveling 3 hours. Chart is optional. Include units in your answer. *

Answer 1

Let, speed of car B is -x.

So, speed of car A is x + 10.

Relative speed of A w.r.t B is ,

`v_(ab)=(x+10)-(-x)\\\\v_(ab)=2x+10\ mph`

So, time taken by A to travel 300 miles relative to B given by 3 hours .

`v_(ab)=2x+10\\\\(300)/(3)=2x+10\\\\x = 45 \ mph`

Therefore, speed of car A is 45 + 10 = 55 mph.

Hence, this is the required solution.