Two detachments went on a hike and are moving with the same speed v = 5 km / h along the same route at a distance.

Two detachments went on a hike and are moving with the same speed v = 5 km / h along the same route at a distance. From one detachment to another went a liaison with a speed v = 6 km / h. on the go handing over the parcel …

Given:
v = 4.0 km / h
l = 2.5 km
v1 = 6.0 km / h

To find:
t -?

1) Calculate the speed of approach of a messenger with another detachment:
v1 sat = v1 – v = 6 – 4 = 2 (km / h);
2) Calculate the time it takes for this to happen:
t1 sat = l / v1 sat = 2.5 / 2 = 1.25 (h);
3) Calculate the speed of approach of a liaison with his squad:
v2 sat = v1 + v = 6 + 4 = 10 (km / h);
4) Calculate the time it takes for this to happen:
t2 sat = l / v2 sat = 2.5 / 10 = 0.25 (h);
5) Calculate the total time:
t = t1 sat + t2 sat = 1.25 + 0.25 = 1.5 (h).

Answer: The messenger performed the assignment for 1.5 hours.