A boat is headed north at a velocity of 8 km/hr. A strong wind whose pressure on the boats superstructure causes it to move side ways to the west at a velocity of 2 km/hr. There is also a tidal current present that flows in a direction 30º south of east at a velocity of 5 km/hr what is the boat's velocity relative to the earth surface?
+1316 This look hard to do but it is not hard if you sort it out. Use vector addition.
North is 0 degrees. South is 180 degrees. N and S will be the Y direction
East is 90. West is 270. E and W will be the X direction.
Use the cos function to give the Y values.
8*cos(0) + 2*cos(270) + 5*cos(120) = 5.5kph in the North direction
Use the sin function to give the X values.
8*sin(0) + 2*sin(270) + 5*sin(120) = 2.3kph in the East direction
Now take the arctan(5.5/2.3) =67.3 degrees. This is the true direction of travel.
Then take sqr(2.3^2 + 5.5^2) =6.0kph. This is the true speed to surface of Earth.
