The velocity of water in a river is less on the bank and large in the middle : why?

Give reason for the following: (a) Machine parts get jammed in the winters. (b) A constant driving force is always required for the maintenance of the flow of oil through pipe lines in the refineries. (c) Velocity of water in a river is less near the banks and more in the middle.

A person reaches on a point directly opposite on the other bank of a river.The velocity of the water in the river is 4 m//s and the velocity of the person in still water is 5 m//s .If the width of the river is 84.6m , time taken to cross the river in seconds is

The velocity of water in a river is 2 kmph ,while width is 400 m . A boat is rowed from a point rowing always aiming opposite point at 8 kmph of still water velocity. On reaching the opposite bank the drift obtained is

The velocity of water in a river is 2 kmph ,while width is 400 m . A boat is rowed from a point rowing always aiming opposite point at 8 kmph of still water velocity. On reaching the opposite bank the drift obtained is

The velocity of a boat in still water is 10 m//s .If water flows in the river with a velocity of 6 m//s what is the difference in times taken to cross the river in the shortest path and the shortest time.The width of the river is 80 m .

The site of Harappa is located on the bank of river

Show that the direction of the shortest route is at right angles to the river when the velocity of the swimmer is greater than that of the river. Show also that when the velocity of the swimmer is less than that of the river, the direction is tan^(-1)v//sqrt(u^(2)-v^(2)) where v= velocity of swimmer and u= velocity of river.

A man swims to and fro along the bank of a river with a velocity v relative to water. If the velocity of flow is u , the average speed of the man (for to and fro motion) is :