A truck left the city at a speed of 60 km / h. At the same time, a truck left the city on the same highway

A truck left the city at a speed of 60 km / h. At the same time, a truck left the city on the same highway in 2 hours, it overtook the truck by 40 km / h at what speed the passenger car was traveling.

1. Speed ​​of the first truck: V1 = 60 km / h;

2. Speed ​​of the second passenger car: V2 km / h;

3. Time of movement of cars: T = 2 hours;

4. During this time, the second car overtook the first by: S = 40 km;

First solution:

5. During the movement, the first car covered the distance: S1 km;

S1 = V1 * T = 60 * 2 = 120 km;

6. Distance driven by the first car: S2 km;

S2 = S1 + S = 120 + 40 = 160 km;

7. Speed ​​of a passenger car:

V2 = S2 / T = 160/2 = 80 km / h;

Second solution:

8. Differential speed of the first and second cars: V km / h;

V = V2 – V1 = (V2 – 60) km / h;

9. Distance of removal of a car from a cargo car:

S = V * T = (V2 – 60) * T;

V2 – 60 = S / T;

V2 = 60 + S / T = 60 + 40/2 = 60 + 20 = 80 km / h.

Answer: the car was traveling at a speed of 80 km / h.