Question

A boat, the speed of which is 10 m.s-1 relative to the water, sails downstream at an angle of 60 degrees, with the flow of the river current. The current flows at 4m.s-1. What is the resultant velocity of the boat?

Answer 1

Answer:

resultant velocity of boat will be 11.2249 m/sec          

Explanation:

We have given speed of boat $v_b$ = 10 m /sec

Velocity pf current flow $v_c$ = 4 m /sec

Angle at which boat is moving = 60°

We have to find the resultant velocity

We know that resultant velocity is given by $v_r=\sqrt{v_b^2+v_c^2+2v_bv_rcos\Theta}=\sqrt{10^2+4^2+2\times 10\times 4cos60^{\circ}}=11.2249m/sec$

So resultant velocity of boat will be 11.2249 m/sec