Respuesta :
If a boat is going East at 15mph and there is a water current going southeast at 45° then the boat is being drifted southward. So since the current is going at an angle then it has a x and y component. So Rx refers to the x-component force of the current and Ry refers to the y-component of the current, and |R| refers to the magnitude of these forces.
Answer:
The boat velocity is 20.6 mph and 14 south of east
Explanation:
For this exercise it is best to write the speeds based on its components x and y
Boat V1x = 15 mph
Water V2 = 7.1 mph
θ = - 45º
Where the angle is measured from the x axis, the negative indicates that it is measured on an hourly basis
V2x = V2 cos (-45) = 7.1 (0.707)
V2y = V2 sin (-45) = 7.1 (-0.707)
V2x = 5.0 mph
V2y = -5.0 mph
The total system speed is the sum of each component
Vx = V1x + V2x
Vy = V1y + V2y
Vx = 15 + 5.0
Vy = 0 -5
Vx = 20 mph
Vy = -5.0 mph
We can give result in the form of magnitude and angle
V² = Vx² + Vy²
θ = tan-1 (Vy / Vx)
V = √ [20² ++ (-5)²]
θ = tan-1 (-5/20)
V = 20.6 mph
θ = -14º
The boat velocity is 20.6 mph and 14 south of east