The own speed of the ship is 27 km / h, the speed of the river is 3 km / h. How much time will the motor
The own speed of the ship is 27 km / h, the speed of the river is 3 km / h. How much time will the motor ship spend on even between two piers, the distance between which is 120 km, if it will sail: a) along the river b) against the river?
Let’s find the speed of the ship along the river.
To do this, add the own speed of the ship to the speed of the river.
27 km / h + 3 km / h = 30 km / h.
Let’s find how long the motor ship will spend on a journey of 120 km along the river.
To do this, we divide this distance by the speed of the ship along the river.
120 km: 30 km / h = 4 hours.
Let’s find the speed of the ship against the river flow.
27 km / h – 3 km / h = 24 km / h.
Let’s find out how much time the motor ship will spend on the route 120 km upstream of the river.
120 km: 24 km / h = 5 hours.