Question

a boat is heading at an angle of 127° from direction of flow.The velocity of boat in water is 5 km/h.The velocity of flow of water is 4km/h.The displacement of boat along flow of water

Answer 1

here boat makes 37degrees with the perpendicular to the flow of water.The velocity of boat with respect to water is 5 kmph.and velocity of river is 3 kmph.
Let velocity of boat is x kmph.Here cos37=x/5=3/5. By equating both we will get x=3kmph.

Answer 2

Answer:

300m

Explanation:

Displacement along flow of water means displacement along x direction (Sx).

velocity of river (Vr) = 4Km/h

width of the river = displacement along y direction (Sy) = 1200m = 1.2Km

velocity of boat Vb = Vb sin37i + Vb cos37 j

t=Sy/Vy = 1.2/4 = 0.3h

same time will be taken for S along x direction

Vx = Vr - Vb sin 37 = 4 - 5*3/5 = 1 Km/h

Sx = Vx/t = 1/0.3 = 0.3 Km = 300m