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A 10 kg box pushed with an initial velocity of 2 m/s on a horizontal surface. The box moves 4 m before it comes to a complete stop. The coefficient of kinetic friction between the box and the surface is

a. 0.51
b. 0.10
c. 0.20
d. 0.051

User Erikest
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1 Answer

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Final answer:

To find the coefficient of kinetic friction between the box and the surface, we can use the equation friction force = coefficient of kinetic friction * normal force. The normal force is equal to the weight of the box, so we can calculate it using the equation normal force = mass * gravity. In this case, the friction force is equal to the force that brings the box to a stop, which can be calculated using the equation friction force = mass * acceleration. Substituting these values into the equation, we can solve for the coefficient of kinetic friction.The option d is the correct answer .

Step-by-step explanation:

To find the coefficient of kinetic friction between the box and the surface, we can use the equation: friction force = coefficient of kinetic friction * normal force. The normal force is equal to the weight of the box, so we can calculate it using the equation: normal force = mass * gravity. In this case, the friction force is equal to the force that brings the box to a stop, which can be calculated using the equation: friction force = mass * acceleration. Substituting these values into the equation, we can solve for the coefficient of kinetic friction.

Given:

  • Mass of the box (m) = 10 kg
  • Initial velocity (v) = 2 m/s
  • Distance traveled before stopping (d) = 4 m

To find the acceleration:

  1. Use the equation: d = (v^2 - u^2) / (2a) where d is the distance, v is the final velocity, u is the initial velocity, and a is the acceleration.
  2. Solve for a: a = (v^2 - u^2) / (2d)
  3. Substitute the given values: a = (0 - 2^2) / (2 * 4)
  4. Simplify: a = -0.5 m/s^2

To find the normal force:

  1. Use the equation: Normal force = mass * gravity
  2. Substitute the given values: Normal force = 10 kg * 9.8 m/s^2
  3. Simplify: Normal force = 98 N

To find the friction force:

  1. Use the equation: friction force = mass * acceleration
  2. Substitute the given values: friction force = 10 kg * (-0.5 m/s^2)
  3. Simplify: friction force = -5 N

To find the coefficient of kinetic friction:

  1. Use the equation: friction force = coefficient of kinetic friction * normal force
  2. Substitute the known values: -5 N = coefficient of kinetic friction * 98 N
  3. Solve for the coefficient of kinetic friction: coefficient of kinetic friction = -5 N / 98 N
  4. Convert to positive value: coefficient of kinetic friction = 0.051

Therefore, the coefficient of kinetic friction between the box and the surface is approximately 0.051.

User Yster
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