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3. A-72 kg man on skis, starting at rest, begins skiing downhill on a slope of 34 degrees. The

coefficient of kinetic friction between his-skis and the snow is 0.17. How fast is he going 4.0
seconds after beginning to move? [Show all work, including the equation and substitution with
units.]
alsin-Ficas

User HardikT
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1 Answer

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Final answer:

To find the speed of the skier after 4.0 seconds, you can calculate the acceleration using the equation a = g*sin(θ) - μ*g*cos(θ) and then use the formula v = u + a*t to find the final velocity. The final velocity of the skier after 4.0 seconds is 7.71 m/s.

Step-by-step explanation:

To find the speed of the skier after 4.0 seconds, we need to calculate the acceleration first. The equation for the acceleration of the skier on a slope is:

a = g*sin(θ) - μ*g*cos(θ)

Where:

  • a is the acceleration
  • g is the acceleration due to gravity (9.8 m/s^2)
  • θ is the angle of the slope (34 degrees)
  • μ is the coefficient of kinetic friction (0.17)

Substituting the values into the equation, we get:

a = (9.8 m/s^2)*sin(34) - (0.17)*(9.8 m/s^2)*cos(34)

Then, we can use the acceleration to find the final velocity of the skier using the formula:

v = u + a*t

Where:

  • v is the final velocity
  • u is the initial velocity (0 m/s, since the skier starts from rest)
  • a is the acceleration
  • t is the time (4.0 seconds)

Substituting the values into the equation, we get:

v = 0 + (9.8 m/s^2)*sin(34)*4.0 s - (0.17)*(9.8 m/s^2)*cos(34)*4.0 s

Simplifying the equation, the final velocity of the skier after 4.0 seconds is 7.71 m/s.

User Benlitz
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