Skiing Downhill

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Skiing Downhill

• Janna Martin
• Physics 2005-2006
• Wauzeka Steuben School District

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A 62-kg person on a skis is going down a hill
sloped at 37.
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The coefficient of kinetic friction between the
skis and the snow is 0.15.
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How fast is the skier going 5 seconds after
starting from rest?
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The initial velocity is 0 meters per second.
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Unknown values are
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There is no acceleration in the y-direction, so
the net force is zero.
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Solve for .
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Solve for .
X-direction
Y-direction
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Solve for .
X-direction
Y-direction
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Solve for .
X-direction
Y-direction
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Solve for .
X-direction
Y-direction
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Solve for .
X-direction
Y-direction
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Solve for .
X-direction
Y-direction
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Solve for .
X-direction
Y-direction
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Solve for .
X-direction
Y-direction
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Use velocity-acceleration relation to find speed.
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Use velocity-acceleration relation to find speed.
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Use velocity-acceleration relation to find speed.
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Lets break the steps down. First you list
everything you know.
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Then figure out when you need to use to figure
the following things
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To figure out acceleration you need to find the
y-direction and the x-direction. Like the diagram
below.
y
x
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Figuring the acceleration
Y-direction
X-direction
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Figuring the acceleration
Y-direction
X-direction
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Figuring the acceleration
Y-direction
X-direction
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Figuring the acceleration
Y-direction
X-direction
Now with this information you can combine the two
equations by substituting in
for . So the equation looks like this
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Figuring the acceleration
Y-direction
X-direction
Factor out m from each side.
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Figuring the acceleration
Y-direction
X-direction
put everything in parentheses
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Figuring the acceleration
Y-direction
X-direction
Factor the g from the parentheses
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Figuring the acceleration
Y-direction
X-direction
Plug in the numbers to the equations
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Figuring the acceleration
Y-direction
X-direction
Finally, solve for a
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Figuring the acceleration
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Now add this to the list of stuff you know.
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Finally, it is time to figure out the final
velocity. Use the equation below
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Plug in the numbers
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Solve
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Now hopefully you have learned how to do a
problem like this.
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The End