The own speed of the ship is 20 km / h, the speed of the river is 3 km / h. The ship went 3 hours along the lake

| January 7, 2021 | education

The own speed of the ship is 20 km / h, the speed of the river is 3 km / h. The ship went 3 hours along the lake and 6 hours against the river. Find the average speed of the ship.

1. The own speed of the ship is equal to: Vc = 20 km / h;
2. The speed of the river is equal to: Vр = 3 km / h;
3. The ship went along the lake: To = 3 hours;
4. On the river the ship went against the current: Tr = 6 hours;
5. Distance covered during the voyage of the ship on the lake: So km;
6. Distance covered during the cruise of the ship along the river: Sp km;
7. Distance covered during the entire sailing period of the ship: S km;
S = So + Sр = Vo * To + (Vс – Vр) * Tr = 20 * 3 + (20 – 3) * 6 = 60 + 102 = 162 km;
8. The average speed of the ship is equal to: V km / h;
V = S / (To + Tr) = 162 / (3 + 6) = 162/9 = 18 km / h.
Answer: the average speed of a motor ship is 18 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.