Mass is how heavy is it, weight is the size both are the same
By Newton's second law, the net vertical force acting on the object is 0, so that
<em>n</em> - <em>w</em> = 0
where <em>n</em> = magnitude of the normal force of the surface pushing up on the object, and <em>w</em> = weight of the object. Hence <em>n</em> = <em>w</em> = <em>mg</em> = 196 N, where <em>m</em> = 20 kg and <em>g</em> = 9.80 m/s².
The force of static friction exerts up to 80 N on the object, since that's the minimum required force needed to get it moving, which means the coefficient of <u>static</u> friction <em>µ</em> is such that
80 N = <em>µ</em> (196 N) → <em>µ</em> = (80 N)/(196 N) ≈ 0.408
Moving at constant speed, there is a kinetic friction force of 40 N opposing the object's motion, so that the coefficient of <u>kinetic</u> friction <em>ν</em> is
40 N = <em>ν</em> (196 N) → <em>ν</em> = (40 N)/(196 N) ≈ 0.204
And so the closest answer is C.
(Note: <em>µ</em> and <em>ν</em> are the Greek letters mu and nu)
¡Hola! Un campo de la psicología son las ramas principales de la psicología. (Por ejemplo, psicología del comportamiento, psicología cognitiva, psicología del desarrollo, psicología de la personalidad). ¡Espero que esto le ayude! Buena suerte y que tengas un gran día. Por cierto, AMO la psicología, ¡así que siéntete libre de hacerme más preguntas al respecto! Además, intente utilizar la versión en español de Brainly para obtener mejores respuestas en su idioma: https://brainly.lat/
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