if vector u has lenght 70 and direction 40 degrees, and vector v has length 85 and direction 335 degrees what is the length and direction of vector u plus vector v

Respuesta :

Answer:

Magnitude of resultant = 131.15

Direction of resultant = 3.97°

Explanation:

||u|| = 70

θ = 40°

[tex]\vec{u}_x=||u||cos\theta \\\Rightarrow \vec{u}_x=70cos40=53.62[/tex]

[tex]\vec{u}_y=||u||sin\theta \\\Rightarrow \vec{u}_y=70sin40=44.99[/tex]

||v|| = 85

θ = 335°

[tex]\vec{v}_x=||v||cos\theta \\\Rightarrow \vec{v}_x=85cos335=77.03[/tex]

[tex]\vec{v}_y=||v||sin\theta \\\Rightarrow \vec{v}_y=85sin335=-35.92[/tex]

Resultant

[tex]R=\sqrt{R_x^2+R_y^2}\\\Rightarrow R=\sqrt{(\vec{u}_x+\vec{v}_x)^2+(\vec{u}_y+\vec{v}_y)^2}\\\Rightarrow R =\sqrt{(70cos40+85cos335)^2+(70sin40+85sin335)^2}\\\Rightarrow R =131.15[/tex]

[tex]\theta=tan^{-1}\frac{R_y}{R_x}\\\Rightarrow \theta=tan^{-1}\frac{70sin40+85sin335}{70cos40+85cos335}\\\Rightarrow \theta=tan^{-1}0.069=3.97^{\circ}[/tex]

Magnitude of resultant = 131.15

Direction of resultant = 3.97°