A canoe has a velocity of 0.330 m/s southeast relative to the earth. The canoe is on a river that is flowing at 0.540 m/s east relative to the earth. Find the velocity (magnitude and direction) of the canoe relative to the river.

Respuesta :

Answer:

The velocity of the canoe relative to the river is 0.385 m/s, S37.26⁰W

Explanation:

Given;

velocity of the canoe relative to the earth, [tex]V_{r/e} = 0.33 \ m/s[/tex]

velocity of the river relative to the earth, [tex]V_{r/e} = 0.54 \ m/s[/tex]

The velocity of the canoe relative to the river is calculated as;

[tex]V_{(c/r)x} = V_{(c/e)x}- V_{(r/e)x} \ \ ----(1)\\\\V_{(c/r)y} = V_{(c/e)y}- V_{(r/e)y} \ \ ----(2)[/tex]

The x - component of the velocity of the canoe relative to the earth;

[tex]V_{(c/e)x} = 0.33 \times cos \ 45^0\\\\V_{(c/e)x} = 0.2333 \ m/s[/tex]

The y-component of the velocity of the canoe relative to the earth;

[tex]V_{(c/e)y} = 0.33 \times sin \ 45^0\\\\V_{(c/e)y} = 0.2333 \ m/s[/tex]

Note: velocity of the river relative to the earth has only x-component = 0.54 m/s

Apply equation (1) and (2) to calculate the velocity of the canoe relative to the river;

[tex]V_{(c/r)}x = 0.2333 - 0.54 = -0.3067 \ m/s\\\\V_{(c/r)}y = 0.2333 - 0 = 0.2333 \ m/s\\\\The \ resultant \ velocity;\\\\V_{c/r} = \sqrt{(-0.3067)^2 + (0.2333)^2} \\\\V_{c/r} = 0.385 \ ms/\\\\The \ direction:\\\\\theta = tan^{-1} (\frac{0.2333}{0.3067} ) = 37.26^0 \ south \ west \ of \ the \ river[/tex]