The car, moving evenly at a speed of 45 km / h, covered the same path in 10 s

The car, moving evenly at a speed of 45 km / h, covered the same path in 10 seconds as a bus moving in the same direction covered in 15 seconds.

Initial data: V1 (speed of uniform movement of the vehicle) = 45 km / h (12.5 m / s); t1 (duration of vehicle movement) = 10 s; t2 (duration of the bus movement) = 15 s; S1 = S2; the car and the bus are moving in the same direction.

1) Determine the speed of the bus from the equality: V1 * t1 = V2 * t2, whence V2 = V1 * t1 / t2 = 12.5 * 10/15 = 8.33 m / s.

2) Let’s calculate the relative speed: ΔV = V1 – V2 = 12.5 – 8.33 = 4.17 m / s.

Answer: The relative speed is 4.17 m / s.