What does velocity in still water means?

Still Water: If the speed of the water is zero, i.e. water is stationary, then it is called still water. When the speed of a boat or a swimmer is given, it usually means speed in still water.

What is drift in river?

Answer: Due to speed of water flow in river, a person either swimming or floating stationary in the river experiences a pushing force along the flow direction. This is known as drift.

What affects the velocity of a river?

The velocity of a river is determined by many factors, including the shape of its channel, the gradient of the slope that the river moves along, the volume of water that the river carries and the amount of friction caused by rough edges within the riverbed.

How does velocity affect the time to cross the river?

The time to cross the river is dependent upon the velocity at which the boat crosses the river. It is only the component of motion directed across the river (i.e., the boat velocity) that affects the time to travel the distance directly across the river (80 m in this case).

How does the river current affect the motion of the boat?

The river current influences the motion of the boat and carries it downstream. The motorboat may be moving with a velocity of 4 m/s directly across the river, yet the resultant velocity of the boat will be greater than 4 m/s and at an angle in the downstream direction.

Why does the boat take more time to cross the river?

In this case the motion of the boat is bit easy because it is supported by the stream of water therefore the boat takes less time to cross the river. Let us consider a case that the boat is moving against the steam of the river. In this case as boat has to overcome the opposition of the river it takes more time.

How do you find the resultant velocity of a motorboat?

The resultant velocity of the motorboat can be determined in the same manner as was done for the plane. The resultant velocity of the boat is the vector sum of the boat velocity and the river velocity.