Practice Set: Acceleration and the coefficient of friction

  1. A 10 kg crate is moving down a wall at a rate of 6 m/s2. A person pushes horizontally in order to stop it. The force of the person is 400 N.
  2. Draw a FBD.
  3. What is the normal force acting on the box? (y-axis)
  4. What is the friction force acting on the box? (x-axis)
  5. Determine the coefficient of friction between the wall and the crate. (Friction Equation)
  1. A 60 kg water skier, initially at rest, is pulled along the water at a rate of 4.2 m/s2. If the coefficient of friction is 0.13,
  2. Draw a FBD.
  3. What is the normal force acting on the box? (y-axis)
  4. What is the friction force acting on the box? (Friction Equation)
  5. what is the tension in the rope? (x-axis)
  1. A 60 kg bicyclist (including bike) coasts along a level road with decreasing speed. If the coefficient of friction is 0.45,
  2. Draw a FBD.
  3. What is the normal force acting on the box? (y-axis)
  4. What is the friction force acting on the box? (friction equation)
  5. what is the acceleration of the bicycle?
  1. A horizontal rope tows a 100-kg water skier with an increasing speed at a rate of 1 m/s2. There is a coefficient of friction of 0.2 between snow and skis opposing the skier.
  2. Draw a FBD.
  3. What is the normal force acting on the box? (y-axis)
  4. What is the friction force acting on the box? (friction equation)
  5. What tension must the rope exert? (x-axis)
  1. A 60 kg skier is pulled along a horizontal ground at constant speed. If the coefficient of friction is 0.1,
  2. Draw a FBD.
  3. What is the normal force acting on the box? (y-axis)
  4. What is the friction force acting on the box? (friction equation)
  5. What tension must the rope exert? (x-axis)


  1. A 10-kg box slides down a 10° incline at a rate of 1.2 m/s2.
  2. Draw a FBD.
  3. Break weight into components.
  4. What is the friction force acting on the box? (Use the x-axis.)
  5. What is the normal force acting on the box? (Use the y-axis.)
  6. What is the coefficient of friction force between the box and the incline? (friction equation)
  7. What would the acceleration be if the coefficient of friction was half as big?
  1. A 50-kg box slides down a 20° incline at a rate of 3 m/s2.
  2. Draw a FBD.
  3. Break weight into components.
  4. What is the friction force acting on the box? (Use the x-axis.)
  5. What is the normal force acting on the box? (Use the y-axis.)
  6. What is the coefficient of friction force between the box and the incline? (friction equation)
  7. What would the acceleration be if the coefficient of friction was half as big?
  1. A 50-kg box slides down a 20° incline at a rate of 3 m/s2.
  2. Draw a FBD.
  3. Break weight into components.
  4. What is the friction force acting on the box? (Use the x-axis.)
  5. What is the normal force acting on the box? (Use the y-axis.)
  6. What is the coefficient of friction force between the box and the incline? (friction equation)
  7. What would the acceleration be if the coefficient of friction was half as big?

X7CoeffFrctnAccel.doc