Home
Class 11
PHYSICS
Water is flowing in a stream with veloci...

Water is flowing in a stream with velocity 5 km/hr in an easterly direction relative to the shore. Speed of a boat is relative to still water is 20 km/hr. If the boat enters the stream heading North, with what velocity will the boat actually travel?

Text Solution

Verified by Experts

The resultant velocity `vecR` of the boat can be obtained by adding the two velocities using `Delta OAB` shown in the figure. Magnitude of the resultant velocity is calculated as follows:

`R=sqrt(20^2+5^2)`
`=sqrt425 =20.61 km//hr`
The direction of the resultant velocity is
`=tan^(-1)(5/20) = tan^(-1) (0.25)=14^0 04. " " :.`
The velocity of the boat is 20.61 km/hr in a direction `14^0 04.` east of north.
Promotional Banner

Similar Questions

Explore conceptually related problems

A man travels by boat 36 km down a river and back in 8 hours. If the speed of his boat in still water is 12 km/hr, find the speed of the river current.

Pratik travels by boat 36 km down a river and back in 8 hours. If the speed of his boat in still water is 12km/hr, find the speed of the river current.

Pratik takes 8 hours to travel 36 km downstream and return to same spot. The speed of boat in still water is 12km/hr. Find the speed of the water current.

The speed of boat is 5 km/hr in still water. It crosses a river of width 1 km along the shortest possible path in 15 minutes. The velocity of the river water is

An aeroplane is travelling northward with a velocity of 300 km/hr with respect to the Earth. Wind is blowing from east to west at a speed of 100 km/hr. What is the velocity of the aeroplane with respect to the wind?

An aeroplane A, is travelling in a straight line with a velocity of 300 km/ hr with respect to Earth . Another aeroplane B, is travelling in the opposite direction with a velocity of 350 km/hr with respect to Earth. What is the relative velocity of A with respect to B? What should be the velocity of a third aeroplane C moving parallel to A, relative to the Earth if it has a relative velocity of 100 km/hr with respect to A?

A swimmer's speed in the direction of flow of rivers is 16 km h^-1 . The swimmer's speed in still water and the velocity of flow of the river respectively are.

A boat is moving with velocity of 3 hat i+ 4hat j in river and water is moving with a velocity of 3 hat i- 4hat j ith respect to ground. Relative velocity of boat with respect to water is

A swimmer's speed in the direction of flow of river is 16 km/h. Against the direction of flow of river, the swimmer's speed is 8 km/h. The swimmer's speed in still water and the velocity of now of the river respectively are