Two cars drove out of points A and B at the same time towards each other. The first covers the distance between A
Two cars drove out of points A and B at the same time towards each other. The first covers the distance between A and B in 3 hours, and the second in 4 hours. Was there a meeting of cars if they are on the way for 1 hour? 2 h?
1. The distance between points A and B is equal to: S km;
2. The first car covers this distance in: T1 = 3 hours;
3. The second car takes time for the whole journey: T2 = 4 hours;
4. Speed of the first car: V1 km / h;
V1 = S / T1 = S / 3;
5. Speed of the second car: V2 km / h;
V2 = S / T2 = S / 4;
6. Let’s calculate the time before the meeting of cars: T hour;
T = S / (V1 + V2) = S / (S / T1 + S / T2) =
S / (S * (1 / T1 + 1 / T2)) = (T1 * T2) / (T1 + T2) =
(3 * 4) / (3 + 4) = (12/7) hours;
7. At the moment of time: Tbc1 = 1 hour;
Tbc = 1 = (7/7) <(12/7), the meeting has not yet taken place;
8. At a point in time: Tbc = 2 hours;
Tbc = 2 = (14/7)> (12/7), the meeting has already taken place.