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Olympic skier Tina Maze skis down a steep slope that descends at an angle of 30∘ below the horizontal. The coefficient of sliding friction between her skis and the snow is 0.10.


I found Maze's acceleration which is 4.1 m/s^2. But how do you determine Maze's speed 4.0 s after starting?

Respuesta :

net force on Maze during his sliding downwards motion

[tex]F = mgsin30 - \mu mg cos30[/tex]

now we will have

[tex]F = mg(sin30 - 0.10cos30)[/tex]

now to find the acceleration we will have

[tex]a = \frac{F}{m}[/tex]

[tex]a = g(sin30 - 0.10cos30)[/tex]

[tex]a = 9.81(0.5 - 0.10(0.866))[/tex]

[tex]a = 4.1 m/s^2[/tex]

now to find the speed after 4 s is given by kinematics

[tex]v_f - v_i = at[/tex]

here we know that

[tex]v_i = 0[/tex]

[tex]v_f - 0 = 4.1(4)[/tex]

[tex]v_f = 16.22 m/s[/tex]

so Maze speed after 4 s will be 16.22 m/s

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