Calculating Friction Force

timer Asked: Jan 27th, 2021

Question Description

Key concepts:

  1. Fnet=ma
  2. The friction force Ff is the force that stops things from sliding, Ff=µN, where N is the normal force, and µ (pronounced “mu”) is the coefficient of friction, a constant which depends only on the surfaces in the problem. See table at right
  3. The normal force stops objects from going through each other and always is perpendicular to a surface.
The weight Fg is the downwards force caused by gravity and can be calculated with Fg=mg, where m is the mass and g=10m/s/s is the acceleration of gravity on Earth.
  1. A 5-kg textbook is sliding along the rough (“rough” means there is friction) ground at 20m/s. What is the weight of the book?

  1. Draw the free body diagram on the dot below

  1. What is the normal force pushing on the textbook?

  1. If μ=0.3, what is the friction force?
  1. What is the net force?
  1. What is the acceleration?

  1. There is a 500-g aluminum soda can on a steel table. What is the weight of the can?

  1. What is the normal force on the can from the table?
  1. Use the table above to find μ and calculate the frictional force that would happen if I tried to push the can sideways
  2. a. A 1000-kg car needs -5m/s/s of acceleration to stop in time. Draw the free body diagram for the car, as the tires slow the car down:
    1. How force is needed from friction to stop the 1000-kg car with -5m/s/s of acceleration?
    1. What are the weight and normal force of the car in part (a)?
    1. What is the coefficient of friction needed for the 1000-kg car to get the amount of friction force needed in part (a)?

    1. Would dry concrete give enough friction (see table above)?

    1. What about wet concrete (see table above)?

Student has agreed that all tutoring, explanations, and answers provided by the tutor will be used to help in the learning process and in accordance with Studypool's honor code & terms of service.

This question has not been answered.

Create a free account to get help with this and any other question!

Brown University

1271 Tutors

California Institute of Technology

2131 Tutors

Carnegie Mellon University

982 Tutors

Columbia University

1256 Tutors

Dartmouth University

2113 Tutors

Emory University

2279 Tutors

Harvard University

599 Tutors

Massachusetts Institute of Technology

2319 Tutors

New York University

1645 Tutors

Notre Dam University

1911 Tutors

Oklahoma University

2122 Tutors

Pennsylvania State University

932 Tutors

Princeton University

1211 Tutors

Stanford University

983 Tutors

University of California

1282 Tutors

Oxford University

123 Tutors

Yale University

2325 Tutors