Answer to Question #7054 in Mechanics | Relativity for Susan

Question

two cars traveling from the same place at the same time and travel in opposite directions. one car travels an average of 20 kph faster than the other. After 2 hours the cars are 40okm apart. find the speed of each car.

Answer 1

Let's the first car speed be V. Then the speed of the other car is V+20 and the distance between them after 2 hours would be
D = 2V + 2(V+20).
From the other side, D=400km. Hence
2V + 2(V+20) = 400 ==> V = 80.
So, the first car's speed is 80km/h and the second one's is 80+20=100km/h.