The tourist passed the first half of the route at a speed of 8 km / h and the second at a speed of 6 km / h

| March 5, 2021 | education

The tourist passed the first half of the route at a speed of 8 km / h and the second at a speed of 6 km / h in 2 hours. With what average speed the tourist was moving.

V1 = 8 km / h.

V2 = 6 km / h.

t2 = 2 h.

S1 = S2 = S / 2.

Vav -?

To find the average speed of movement Vav, it is necessary to divide the entire path S traveled by the tourist by the time of his movement t: Vav = S / t.

The travel time of the entire path is expressed by the sum: t = t1 + t2, where t1 is the travel time of the tourist on the first half of the journey, t2 is the travel time on the second half of the journey.

t1 = S1 / V1.

Since S1 = S2 = S / 2, then S1 = V2 * t2.

t1 = S1 / V1 = S2 / V1 = V2 * t2 / V1.

t1 = 6 km / h * 2 h / 8 km / h = 1.5 h.

t = 1.5 h + 2 h = 3.5 h.

S = S1 + S2 = V2 * t2 + V2 * t2 = 2 * V2 * t2.

S = 2 * 6 km / h * 2 h = 24 km.

Vav = 24 km / 3.5 h = 6.9 km / h.

Answer: the average speed of a tourist along the entire path is Vav = 6.9 km / h.



One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.